1 // SPDX-License-Identifier: GPL-2.0-or-later
3 Copyright (C) 2002 Richard Henderson
4 Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
8 #define INCLUDE_VERMAGIC
10 #include <linux/export.h>
11 #include <linux/extable.h>
12 #include <linux/moduleloader.h>
13 #include <linux/module_signature.h>
14 #include <linux/trace_events.h>
15 #include <linux/init.h>
16 #include <linux/kallsyms.h>
17 #include <linux/file.h>
19 #include <linux/sysfs.h>
20 #include <linux/kernel.h>
21 #include <linux/slab.h>
22 #include <linux/vmalloc.h>
23 #include <linux/elf.h>
24 #include <linux/proc_fs.h>
25 #include <linux/security.h>
26 #include <linux/seq_file.h>
27 #include <linux/syscalls.h>
28 #include <linux/fcntl.h>
29 #include <linux/rcupdate.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/moduleparam.h>
33 #include <linux/errno.h>
34 #include <linux/err.h>
35 #include <linux/vermagic.h>
36 #include <linux/notifier.h>
37 #include <linux/sched.h>
38 #include <linux/device.h>
39 #include <linux/string.h>
40 #include <linux/mutex.h>
41 #include <linux/rculist.h>
42 #include <linux/uaccess.h>
43 #include <asm/cacheflush.h>
44 #include <linux/set_memory.h>
45 #include <asm/mmu_context.h>
46 #include <linux/license.h>
47 #include <asm/sections.h>
48 #include <linux/tracepoint.h>
49 #include <linux/ftrace.h>
50 #include <linux/livepatch.h>
51 #include <linux/async.h>
52 #include <linux/percpu.h>
53 #include <linux/kmemleak.h>
54 #include <linux/jump_label.h>
55 #include <linux/pfn.h>
56 #include <linux/bsearch.h>
57 #include <linux/dynamic_debug.h>
58 #include <linux/audit.h>
59 #include <uapi/linux/module.h>
60 #include "module-internal.h"
62 #define CREATE_TRACE_POINTS
63 #include <trace/events/module.h>
65 #ifndef ARCH_SHF_SMALL
66 #define ARCH_SHF_SMALL 0
70 * Modules' sections will be aligned on page boundaries
71 * to ensure complete separation of code and data, but
72 * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y
74 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
75 # define debug_align(X) ALIGN(X, PAGE_SIZE)
77 # define debug_align(X) (X)
80 /* If this is set, the section belongs in the init part of the module */
81 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
85 * 1) List of modules (also safely readable with preempt_disable),
86 * 2) module_use links,
87 * 3) module_addr_min/module_addr_max.
88 * (delete and add uses RCU list operations). */
89 DEFINE_MUTEX(module_mutex
);
90 EXPORT_SYMBOL_GPL(module_mutex
);
91 static LIST_HEAD(modules
);
93 /* Work queue for freeing init sections in success case */
94 static struct work_struct init_free_wq
;
95 static struct llist_head init_free_list
;
97 #ifdef CONFIG_MODULES_TREE_LOOKUP
100 * Use a latched RB-tree for __module_address(); this allows us to use
101 * RCU-sched lookups of the address from any context.
103 * This is conditional on PERF_EVENTS || TRACING because those can really hit
104 * __module_address() hard by doing a lot of stack unwinding; potentially from
108 static __always_inline
unsigned long __mod_tree_val(struct latch_tree_node
*n
)
110 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
112 return (unsigned long)layout
->base
;
115 static __always_inline
unsigned long __mod_tree_size(struct latch_tree_node
*n
)
117 struct module_layout
*layout
= container_of(n
, struct module_layout
, mtn
.node
);
119 return (unsigned long)layout
->size
;
122 static __always_inline
bool
123 mod_tree_less(struct latch_tree_node
*a
, struct latch_tree_node
*b
)
125 return __mod_tree_val(a
) < __mod_tree_val(b
);
128 static __always_inline
int
129 mod_tree_comp(void *key
, struct latch_tree_node
*n
)
131 unsigned long val
= (unsigned long)key
;
132 unsigned long start
, end
;
134 start
= __mod_tree_val(n
);
138 end
= start
+ __mod_tree_size(n
);
145 static const struct latch_tree_ops mod_tree_ops
= {
146 .less
= mod_tree_less
,
147 .comp
= mod_tree_comp
,
150 static struct mod_tree_root
{
151 struct latch_tree_root root
;
152 unsigned long addr_min
;
153 unsigned long addr_max
;
154 } mod_tree __cacheline_aligned
= {
158 #define module_addr_min mod_tree.addr_min
159 #define module_addr_max mod_tree.addr_max
161 static noinline
void __mod_tree_insert(struct mod_tree_node
*node
)
163 latch_tree_insert(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
166 static void __mod_tree_remove(struct mod_tree_node
*node
)
168 latch_tree_erase(&node
->node
, &mod_tree
.root
, &mod_tree_ops
);
172 * These modifications: insert, remove_init and remove; are serialized by the
175 static void mod_tree_insert(struct module
*mod
)
177 mod
->core_layout
.mtn
.mod
= mod
;
178 mod
->init_layout
.mtn
.mod
= mod
;
180 __mod_tree_insert(&mod
->core_layout
.mtn
);
181 if (mod
->init_layout
.size
)
182 __mod_tree_insert(&mod
->init_layout
.mtn
);
185 static void mod_tree_remove_init(struct module
*mod
)
187 if (mod
->init_layout
.size
)
188 __mod_tree_remove(&mod
->init_layout
.mtn
);
191 static void mod_tree_remove(struct module
*mod
)
193 __mod_tree_remove(&mod
->core_layout
.mtn
);
194 mod_tree_remove_init(mod
);
197 static struct module
*mod_find(unsigned long addr
)
199 struct latch_tree_node
*ltn
;
201 ltn
= latch_tree_find((void *)addr
, &mod_tree
.root
, &mod_tree_ops
);
205 return container_of(ltn
, struct mod_tree_node
, node
)->mod
;
208 #else /* MODULES_TREE_LOOKUP */
210 static unsigned long module_addr_min
= -1UL, module_addr_max
= 0;
212 static void mod_tree_insert(struct module
*mod
) { }
213 static void mod_tree_remove_init(struct module
*mod
) { }
214 static void mod_tree_remove(struct module
*mod
) { }
216 static struct module
*mod_find(unsigned long addr
)
220 list_for_each_entry_rcu(mod
, &modules
, list
,
221 lockdep_is_held(&module_mutex
)) {
222 if (within_module(addr
, mod
))
229 #endif /* MODULES_TREE_LOOKUP */
232 * Bounds of module text, for speeding up __module_address.
233 * Protected by module_mutex.
235 static void __mod_update_bounds(void *base
, unsigned int size
)
237 unsigned long min
= (unsigned long)base
;
238 unsigned long max
= min
+ size
;
240 if (min
< module_addr_min
)
241 module_addr_min
= min
;
242 if (max
> module_addr_max
)
243 module_addr_max
= max
;
246 static void mod_update_bounds(struct module
*mod
)
248 __mod_update_bounds(mod
->core_layout
.base
, mod
->core_layout
.size
);
249 if (mod
->init_layout
.size
)
250 __mod_update_bounds(mod
->init_layout
.base
, mod
->init_layout
.size
);
253 #ifdef CONFIG_KGDB_KDB
254 struct list_head
*kdb_modules
= &modules
; /* kdb needs the list of modules */
255 #endif /* CONFIG_KGDB_KDB */
257 static void module_assert_mutex(void)
259 lockdep_assert_held(&module_mutex
);
262 static void module_assert_mutex_or_preempt(void)
264 #ifdef CONFIG_LOCKDEP
265 if (unlikely(!debug_locks
))
268 WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
269 !lockdep_is_held(&module_mutex
));
273 static bool sig_enforce
= IS_ENABLED(CONFIG_MODULE_SIG_FORCE
);
274 module_param(sig_enforce
, bool_enable_only
, 0644);
277 * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
278 * on that instead of directly to CONFIG_MODULE_SIG_FORCE config.
280 bool is_module_sig_enforced(void)
284 EXPORT_SYMBOL(is_module_sig_enforced
);
286 void set_module_sig_enforced(void)
291 /* Block module loading/unloading? */
292 int modules_disabled
= 0;
293 core_param(nomodule
, modules_disabled
, bint
, 0);
295 /* Waiting for a module to finish initializing? */
296 static DECLARE_WAIT_QUEUE_HEAD(module_wq
);
298 static BLOCKING_NOTIFIER_HEAD(module_notify_list
);
300 int register_module_notifier(struct notifier_block
*nb
)
302 return blocking_notifier_chain_register(&module_notify_list
, nb
);
304 EXPORT_SYMBOL(register_module_notifier
);
306 int unregister_module_notifier(struct notifier_block
*nb
)
308 return blocking_notifier_chain_unregister(&module_notify_list
, nb
);
310 EXPORT_SYMBOL(unregister_module_notifier
);
313 * We require a truly strong try_module_get(): 0 means success.
314 * Otherwise an error is returned due to ongoing or failed
315 * initialization etc.
317 static inline int strong_try_module_get(struct module
*mod
)
319 BUG_ON(mod
&& mod
->state
== MODULE_STATE_UNFORMED
);
320 if (mod
&& mod
->state
== MODULE_STATE_COMING
)
322 if (try_module_get(mod
))
328 static inline void add_taint_module(struct module
*mod
, unsigned flag
,
329 enum lockdep_ok lockdep_ok
)
331 add_taint(flag
, lockdep_ok
);
332 set_bit(flag
, &mod
->taints
);
336 * A thread that wants to hold a reference to a module only while it
337 * is running can call this to safely exit. nfsd and lockd use this.
339 void __noreturn
__module_put_and_exit(struct module
*mod
, long code
)
344 EXPORT_SYMBOL(__module_put_and_exit
);
346 /* Find a module section: 0 means not found. */
347 static unsigned int find_sec(const struct load_info
*info
, const char *name
)
351 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
352 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
353 /* Alloc bit cleared means "ignore it." */
354 if ((shdr
->sh_flags
& SHF_ALLOC
)
355 && strcmp(info
->secstrings
+ shdr
->sh_name
, name
) == 0)
361 /* Find a module section, or NULL. */
362 static void *section_addr(const struct load_info
*info
, const char *name
)
364 /* Section 0 has sh_addr 0. */
365 return (void *)info
->sechdrs
[find_sec(info
, name
)].sh_addr
;
368 /* Find a module section, or NULL. Fill in number of "objects" in section. */
369 static void *section_objs(const struct load_info
*info
,
374 unsigned int sec
= find_sec(info
, name
);
376 /* Section 0 has sh_addr 0 and sh_size 0. */
377 *num
= info
->sechdrs
[sec
].sh_size
/ object_size
;
378 return (void *)info
->sechdrs
[sec
].sh_addr
;
381 /* Provided by the linker */
382 extern const struct kernel_symbol __start___ksymtab
[];
383 extern const struct kernel_symbol __stop___ksymtab
[];
384 extern const struct kernel_symbol __start___ksymtab_gpl
[];
385 extern const struct kernel_symbol __stop___ksymtab_gpl
[];
386 extern const struct kernel_symbol __start___ksymtab_gpl_future
[];
387 extern const struct kernel_symbol __stop___ksymtab_gpl_future
[];
388 extern const s32 __start___kcrctab
[];
389 extern const s32 __start___kcrctab_gpl
[];
390 extern const s32 __start___kcrctab_gpl_future
[];
391 #ifdef CONFIG_UNUSED_SYMBOLS
392 extern const struct kernel_symbol __start___ksymtab_unused
[];
393 extern const struct kernel_symbol __stop___ksymtab_unused
[];
394 extern const struct kernel_symbol __start___ksymtab_unused_gpl
[];
395 extern const struct kernel_symbol __stop___ksymtab_unused_gpl
[];
396 extern const s32 __start___kcrctab_unused
[];
397 extern const s32 __start___kcrctab_unused_gpl
[];
400 #ifndef CONFIG_MODVERSIONS
401 #define symversion(base, idx) NULL
403 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
406 static bool each_symbol_in_section(const struct symsearch
*arr
,
407 unsigned int arrsize
,
408 struct module
*owner
,
409 bool (*fn
)(const struct symsearch
*syms
,
410 struct module
*owner
,
416 for (j
= 0; j
< arrsize
; j
++) {
417 if (fn(&arr
[j
], owner
, data
))
424 /* Returns true as soon as fn returns true, otherwise false. */
425 static bool each_symbol_section(bool (*fn
)(const struct symsearch
*arr
,
426 struct module
*owner
,
431 static const struct symsearch arr
[] = {
432 { __start___ksymtab
, __stop___ksymtab
, __start___kcrctab
,
433 NOT_GPL_ONLY
, false },
434 { __start___ksymtab_gpl
, __stop___ksymtab_gpl
,
435 __start___kcrctab_gpl
,
437 { __start___ksymtab_gpl_future
, __stop___ksymtab_gpl_future
,
438 __start___kcrctab_gpl_future
,
439 WILL_BE_GPL_ONLY
, false },
440 #ifdef CONFIG_UNUSED_SYMBOLS
441 { __start___ksymtab_unused
, __stop___ksymtab_unused
,
442 __start___kcrctab_unused
,
443 NOT_GPL_ONLY
, true },
444 { __start___ksymtab_unused_gpl
, __stop___ksymtab_unused_gpl
,
445 __start___kcrctab_unused_gpl
,
450 module_assert_mutex_or_preempt();
452 if (each_symbol_in_section(arr
, ARRAY_SIZE(arr
), NULL
, fn
, data
))
455 list_for_each_entry_rcu(mod
, &modules
, list
,
456 lockdep_is_held(&module_mutex
)) {
457 struct symsearch arr
[] = {
458 { mod
->syms
, mod
->syms
+ mod
->num_syms
, mod
->crcs
,
459 NOT_GPL_ONLY
, false },
460 { mod
->gpl_syms
, mod
->gpl_syms
+ mod
->num_gpl_syms
,
463 { mod
->gpl_future_syms
,
464 mod
->gpl_future_syms
+ mod
->num_gpl_future_syms
,
465 mod
->gpl_future_crcs
,
466 WILL_BE_GPL_ONLY
, false },
467 #ifdef CONFIG_UNUSED_SYMBOLS
469 mod
->unused_syms
+ mod
->num_unused_syms
,
471 NOT_GPL_ONLY
, true },
472 { mod
->unused_gpl_syms
,
473 mod
->unused_gpl_syms
+ mod
->num_unused_gpl_syms
,
474 mod
->unused_gpl_crcs
,
479 if (mod
->state
== MODULE_STATE_UNFORMED
)
482 if (each_symbol_in_section(arr
, ARRAY_SIZE(arr
), mod
, fn
, data
))
488 struct find_symbol_arg
{
495 struct module
*owner
;
497 const struct kernel_symbol
*sym
;
498 enum mod_license license
;
501 static bool check_exported_symbol(const struct symsearch
*syms
,
502 struct module
*owner
,
503 unsigned int symnum
, void *data
)
505 struct find_symbol_arg
*fsa
= data
;
508 if (syms
->license
== GPL_ONLY
)
510 if (syms
->license
== WILL_BE_GPL_ONLY
&& fsa
->warn
) {
511 pr_warn("Symbol %s is being used by a non-GPL module, "
512 "which will not be allowed in the future\n",
517 #ifdef CONFIG_UNUSED_SYMBOLS
518 if (syms
->unused
&& fsa
->warn
) {
519 pr_warn("Symbol %s is marked as UNUSED, however this module is "
520 "using it.\n", fsa
->name
);
521 pr_warn("This symbol will go away in the future.\n");
522 pr_warn("Please evaluate if this is the right api to use and "
523 "if it really is, submit a report to the linux kernel "
524 "mailing list together with submitting your code for "
530 fsa
->crc
= symversion(syms
->crcs
, symnum
);
531 fsa
->sym
= &syms
->start
[symnum
];
532 fsa
->license
= syms
->license
;
536 static unsigned long kernel_symbol_value(const struct kernel_symbol
*sym
)
538 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
539 return (unsigned long)offset_to_ptr(&sym
->value_offset
);
545 static const char *kernel_symbol_name(const struct kernel_symbol
*sym
)
547 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
548 return offset_to_ptr(&sym
->name_offset
);
554 static const char *kernel_symbol_namespace(const struct kernel_symbol
*sym
)
556 #ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
557 if (!sym
->namespace_offset
)
559 return offset_to_ptr(&sym
->namespace_offset
);
561 return sym
->namespace;
565 static int cmp_name(const void *name
, const void *sym
)
567 return strcmp(name
, kernel_symbol_name(sym
));
570 static bool find_exported_symbol_in_section(const struct symsearch
*syms
,
571 struct module
*owner
,
574 struct find_symbol_arg
*fsa
= data
;
575 struct kernel_symbol
*sym
;
577 sym
= bsearch(fsa
->name
, syms
->start
, syms
->stop
- syms
->start
,
578 sizeof(struct kernel_symbol
), cmp_name
);
580 if (sym
!= NULL
&& check_exported_symbol(syms
, owner
,
581 sym
- syms
->start
, data
))
587 /* Find an exported symbol and return it, along with, (optional) crc and
588 * (optional) module which owns it. Needs preempt disabled or module_mutex. */
589 static const struct kernel_symbol
*find_symbol(const char *name
,
590 struct module
**owner
,
592 enum mod_license
*license
,
596 struct find_symbol_arg fsa
;
602 if (each_symbol_section(find_exported_symbol_in_section
, &fsa
)) {
608 *license
= fsa
.license
;
612 pr_debug("Failed to find symbol %s\n", name
);
617 * Search for module by name: must hold module_mutex (or preempt disabled
618 * for read-only access).
620 static struct module
*find_module_all(const char *name
, size_t len
,
625 module_assert_mutex_or_preempt();
627 list_for_each_entry_rcu(mod
, &modules
, list
,
628 lockdep_is_held(&module_mutex
)) {
629 if (!even_unformed
&& mod
->state
== MODULE_STATE_UNFORMED
)
631 if (strlen(mod
->name
) == len
&& !memcmp(mod
->name
, name
, len
))
637 struct module
*find_module(const char *name
)
639 module_assert_mutex();
640 return find_module_all(name
, strlen(name
), false);
642 EXPORT_SYMBOL_GPL(find_module
);
646 static inline void __percpu
*mod_percpu(struct module
*mod
)
651 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
653 Elf_Shdr
*pcpusec
= &info
->sechdrs
[info
->index
.pcpu
];
654 unsigned long align
= pcpusec
->sh_addralign
;
656 if (!pcpusec
->sh_size
)
659 if (align
> PAGE_SIZE
) {
660 pr_warn("%s: per-cpu alignment %li > %li\n",
661 mod
->name
, align
, PAGE_SIZE
);
665 mod
->percpu
= __alloc_reserved_percpu(pcpusec
->sh_size
, align
);
667 pr_warn("%s: Could not allocate %lu bytes percpu data\n",
668 mod
->name
, (unsigned long)pcpusec
->sh_size
);
671 mod
->percpu_size
= pcpusec
->sh_size
;
675 static void percpu_modfree(struct module
*mod
)
677 free_percpu(mod
->percpu
);
680 static unsigned int find_pcpusec(struct load_info
*info
)
682 return find_sec(info
, ".data..percpu");
685 static void percpu_modcopy(struct module
*mod
,
686 const void *from
, unsigned long size
)
690 for_each_possible_cpu(cpu
)
691 memcpy(per_cpu_ptr(mod
->percpu
, cpu
), from
, size
);
694 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
701 list_for_each_entry_rcu(mod
, &modules
, list
) {
702 if (mod
->state
== MODULE_STATE_UNFORMED
)
704 if (!mod
->percpu_size
)
706 for_each_possible_cpu(cpu
) {
707 void *start
= per_cpu_ptr(mod
->percpu
, cpu
);
708 void *va
= (void *)addr
;
710 if (va
>= start
&& va
< start
+ mod
->percpu_size
) {
712 *can_addr
= (unsigned long) (va
- start
);
713 *can_addr
+= (unsigned long)
714 per_cpu_ptr(mod
->percpu
,
728 * is_module_percpu_address - test whether address is from module static percpu
729 * @addr: address to test
731 * Test whether @addr belongs to module static percpu area.
734 * %true if @addr is from module static percpu area
736 bool is_module_percpu_address(unsigned long addr
)
738 return __is_module_percpu_address(addr
, NULL
);
741 #else /* ... !CONFIG_SMP */
743 static inline void __percpu
*mod_percpu(struct module
*mod
)
747 static int percpu_modalloc(struct module
*mod
, struct load_info
*info
)
749 /* UP modules shouldn't have this section: ENOMEM isn't quite right */
750 if (info
->sechdrs
[info
->index
.pcpu
].sh_size
!= 0)
754 static inline void percpu_modfree(struct module
*mod
)
757 static unsigned int find_pcpusec(struct load_info
*info
)
761 static inline void percpu_modcopy(struct module
*mod
,
762 const void *from
, unsigned long size
)
764 /* pcpusec should be 0, and size of that section should be 0. */
767 bool is_module_percpu_address(unsigned long addr
)
772 bool __is_module_percpu_address(unsigned long addr
, unsigned long *can_addr
)
777 #endif /* CONFIG_SMP */
779 #define MODINFO_ATTR(field) \
780 static void setup_modinfo_##field(struct module *mod, const char *s) \
782 mod->field = kstrdup(s, GFP_KERNEL); \
784 static ssize_t show_modinfo_##field(struct module_attribute *mattr, \
785 struct module_kobject *mk, char *buffer) \
787 return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \
789 static int modinfo_##field##_exists(struct module *mod) \
791 return mod->field != NULL; \
793 static void free_modinfo_##field(struct module *mod) \
798 static struct module_attribute modinfo_##field = { \
799 .attr = { .name = __stringify(field), .mode = 0444 }, \
800 .show = show_modinfo_##field, \
801 .setup = setup_modinfo_##field, \
802 .test = modinfo_##field##_exists, \
803 .free = free_modinfo_##field, \
806 MODINFO_ATTR(version
);
807 MODINFO_ATTR(srcversion
);
809 static char last_unloaded_module
[MODULE_NAME_LEN
+1];
811 #ifdef CONFIG_MODULE_UNLOAD
813 EXPORT_TRACEPOINT_SYMBOL(module_get
);
815 /* MODULE_REF_BASE is the base reference count by kmodule loader. */
816 #define MODULE_REF_BASE 1
818 /* Init the unload section of the module. */
819 static int module_unload_init(struct module
*mod
)
822 * Initialize reference counter to MODULE_REF_BASE.
823 * refcnt == 0 means module is going.
825 atomic_set(&mod
->refcnt
, MODULE_REF_BASE
);
827 INIT_LIST_HEAD(&mod
->source_list
);
828 INIT_LIST_HEAD(&mod
->target_list
);
830 /* Hold reference count during initialization. */
831 atomic_inc(&mod
->refcnt
);
836 /* Does a already use b? */
837 static int already_uses(struct module
*a
, struct module
*b
)
839 struct module_use
*use
;
841 list_for_each_entry(use
, &b
->source_list
, source_list
) {
842 if (use
->source
== a
) {
843 pr_debug("%s uses %s!\n", a
->name
, b
->name
);
847 pr_debug("%s does not use %s!\n", a
->name
, b
->name
);
853 * - we add 'a' as a "source", 'b' as a "target" of module use
854 * - the module_use is added to the list of 'b' sources (so
855 * 'b' can walk the list to see who sourced them), and of 'a'
856 * targets (so 'a' can see what modules it targets).
858 static int add_module_usage(struct module
*a
, struct module
*b
)
860 struct module_use
*use
;
862 pr_debug("Allocating new usage for %s.\n", a
->name
);
863 use
= kmalloc(sizeof(*use
), GFP_ATOMIC
);
869 list_add(&use
->source_list
, &b
->source_list
);
870 list_add(&use
->target_list
, &a
->target_list
);
874 /* Module a uses b: caller needs module_mutex() */
875 static int ref_module(struct module
*a
, struct module
*b
)
879 if (b
== NULL
|| already_uses(a
, b
))
882 /* If module isn't available, we fail. */
883 err
= strong_try_module_get(b
);
887 err
= add_module_usage(a
, b
);
895 /* Clear the unload stuff of the module. */
896 static void module_unload_free(struct module
*mod
)
898 struct module_use
*use
, *tmp
;
900 mutex_lock(&module_mutex
);
901 list_for_each_entry_safe(use
, tmp
, &mod
->target_list
, target_list
) {
902 struct module
*i
= use
->target
;
903 pr_debug("%s unusing %s\n", mod
->name
, i
->name
);
905 list_del(&use
->source_list
);
906 list_del(&use
->target_list
);
909 mutex_unlock(&module_mutex
);
912 #ifdef CONFIG_MODULE_FORCE_UNLOAD
913 static inline int try_force_unload(unsigned int flags
)
915 int ret
= (flags
& O_TRUNC
);
917 add_taint(TAINT_FORCED_RMMOD
, LOCKDEP_NOW_UNRELIABLE
);
921 static inline int try_force_unload(unsigned int flags
)
925 #endif /* CONFIG_MODULE_FORCE_UNLOAD */
927 /* Try to release refcount of module, 0 means success. */
928 static int try_release_module_ref(struct module
*mod
)
932 /* Try to decrement refcnt which we set at loading */
933 ret
= atomic_sub_return(MODULE_REF_BASE
, &mod
->refcnt
);
936 /* Someone can put this right now, recover with checking */
937 ret
= atomic_add_unless(&mod
->refcnt
, MODULE_REF_BASE
, 0);
942 static int try_stop_module(struct module
*mod
, int flags
, int *forced
)
944 /* If it's not unused, quit unless we're forcing. */
945 if (try_release_module_ref(mod
) != 0) {
946 *forced
= try_force_unload(flags
);
951 /* Mark it as dying. */
952 mod
->state
= MODULE_STATE_GOING
;
958 * module_refcount - return the refcount or -1 if unloading
960 * @mod: the module we're checking
963 * -1 if the module is in the process of unloading
964 * otherwise the number of references in the kernel to the module
966 int module_refcount(struct module
*mod
)
968 return atomic_read(&mod
->refcnt
) - MODULE_REF_BASE
;
970 EXPORT_SYMBOL(module_refcount
);
972 /* This exists whether we can unload or not */
973 static void free_module(struct module
*mod
);
975 SYSCALL_DEFINE2(delete_module
, const char __user
*, name_user
,
979 char name
[MODULE_NAME_LEN
];
982 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
985 if (strncpy_from_user(name
, name_user
, MODULE_NAME_LEN
-1) < 0)
987 name
[MODULE_NAME_LEN
-1] = '\0';
989 audit_log_kern_module(name
);
991 if (mutex_lock_interruptible(&module_mutex
) != 0)
994 mod
= find_module(name
);
1000 if (!list_empty(&mod
->source_list
)) {
1001 /* Other modules depend on us: get rid of them first. */
1006 /* Doing init or already dying? */
1007 if (mod
->state
!= MODULE_STATE_LIVE
) {
1008 /* FIXME: if (force), slam module count damn the torpedoes */
1009 pr_debug("%s already dying\n", mod
->name
);
1014 /* If it has an init func, it must have an exit func to unload */
1015 if (mod
->init
&& !mod
->exit
) {
1016 forced
= try_force_unload(flags
);
1018 /* This module can't be removed */
1024 /* Stop the machine so refcounts can't move and disable module. */
1025 ret
= try_stop_module(mod
, flags
, &forced
);
1029 mutex_unlock(&module_mutex
);
1030 /* Final destruction now no one is using it. */
1031 if (mod
->exit
!= NULL
)
1033 blocking_notifier_call_chain(&module_notify_list
,
1034 MODULE_STATE_GOING
, mod
);
1035 klp_module_going(mod
);
1036 ftrace_release_mod(mod
);
1038 async_synchronize_full();
1040 /* Store the name of the last unloaded module for diagnostic purposes */
1041 strlcpy(last_unloaded_module
, mod
->name
, sizeof(last_unloaded_module
));
1044 /* someone could wait for the module in add_unformed_module() */
1045 wake_up_all(&module_wq
);
1048 mutex_unlock(&module_mutex
);
1052 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
1054 struct module_use
*use
;
1055 int printed_something
= 0;
1057 seq_printf(m
, " %i ", module_refcount(mod
));
1060 * Always include a trailing , so userspace can differentiate
1061 * between this and the old multi-field proc format.
1063 list_for_each_entry(use
, &mod
->source_list
, source_list
) {
1064 printed_something
= 1;
1065 seq_printf(m
, "%s,", use
->source
->name
);
1068 if (mod
->init
!= NULL
&& mod
->exit
== NULL
) {
1069 printed_something
= 1;
1070 seq_puts(m
, "[permanent],");
1073 if (!printed_something
)
1077 void __symbol_put(const char *symbol
)
1079 struct module
*owner
;
1082 if (!find_symbol(symbol
, &owner
, NULL
, NULL
, true, false))
1087 EXPORT_SYMBOL(__symbol_put
);
1089 /* Note this assumes addr is a function, which it currently always is. */
1090 void symbol_put_addr(void *addr
)
1092 struct module
*modaddr
;
1093 unsigned long a
= (unsigned long)dereference_function_descriptor(addr
);
1095 if (core_kernel_text(a
))
1099 * Even though we hold a reference on the module; we still need to
1100 * disable preemption in order to safely traverse the data structure.
1103 modaddr
= __module_text_address(a
);
1105 module_put(modaddr
);
1108 EXPORT_SYMBOL_GPL(symbol_put_addr
);
1110 static ssize_t
show_refcnt(struct module_attribute
*mattr
,
1111 struct module_kobject
*mk
, char *buffer
)
1113 return sprintf(buffer
, "%i\n", module_refcount(mk
->mod
));
1116 static struct module_attribute modinfo_refcnt
=
1117 __ATTR(refcnt
, 0444, show_refcnt
, NULL
);
1119 void __module_get(struct module
*module
)
1123 atomic_inc(&module
->refcnt
);
1124 trace_module_get(module
, _RET_IP_
);
1128 EXPORT_SYMBOL(__module_get
);
1130 bool try_module_get(struct module
*module
)
1136 /* Note: here, we can fail to get a reference */
1137 if (likely(module_is_live(module
) &&
1138 atomic_inc_not_zero(&module
->refcnt
) != 0))
1139 trace_module_get(module
, _RET_IP_
);
1147 EXPORT_SYMBOL(try_module_get
);
1149 void module_put(struct module
*module
)
1155 ret
= atomic_dec_if_positive(&module
->refcnt
);
1156 WARN_ON(ret
< 0); /* Failed to put refcount */
1157 trace_module_put(module
, _RET_IP_
);
1161 EXPORT_SYMBOL(module_put
);
1163 #else /* !CONFIG_MODULE_UNLOAD */
1164 static inline void print_unload_info(struct seq_file
*m
, struct module
*mod
)
1166 /* We don't know the usage count, or what modules are using. */
1167 seq_puts(m
, " - -");
1170 static inline void module_unload_free(struct module
*mod
)
1174 static int ref_module(struct module
*a
, struct module
*b
)
1176 return strong_try_module_get(b
);
1179 static inline int module_unload_init(struct module
*mod
)
1183 #endif /* CONFIG_MODULE_UNLOAD */
1185 static size_t module_flags_taint(struct module
*mod
, char *buf
)
1190 for (i
= 0; i
< TAINT_FLAGS_COUNT
; i
++) {
1191 if (taint_flags
[i
].module
&& test_bit(i
, &mod
->taints
))
1192 buf
[l
++] = taint_flags
[i
].c_true
;
1198 static ssize_t
show_initstate(struct module_attribute
*mattr
,
1199 struct module_kobject
*mk
, char *buffer
)
1201 const char *state
= "unknown";
1203 switch (mk
->mod
->state
) {
1204 case MODULE_STATE_LIVE
:
1207 case MODULE_STATE_COMING
:
1210 case MODULE_STATE_GOING
:
1216 return sprintf(buffer
, "%s\n", state
);
1219 static struct module_attribute modinfo_initstate
=
1220 __ATTR(initstate
, 0444, show_initstate
, NULL
);
1222 static ssize_t
store_uevent(struct module_attribute
*mattr
,
1223 struct module_kobject
*mk
,
1224 const char *buffer
, size_t count
)
1228 rc
= kobject_synth_uevent(&mk
->kobj
, buffer
, count
);
1229 return rc
? rc
: count
;
1232 struct module_attribute module_uevent
=
1233 __ATTR(uevent
, 0200, NULL
, store_uevent
);
1235 static ssize_t
show_coresize(struct module_attribute
*mattr
,
1236 struct module_kobject
*mk
, char *buffer
)
1238 return sprintf(buffer
, "%u\n", mk
->mod
->core_layout
.size
);
1241 static struct module_attribute modinfo_coresize
=
1242 __ATTR(coresize
, 0444, show_coresize
, NULL
);
1244 static ssize_t
show_initsize(struct module_attribute
*mattr
,
1245 struct module_kobject
*mk
, char *buffer
)
1247 return sprintf(buffer
, "%u\n", mk
->mod
->init_layout
.size
);
1250 static struct module_attribute modinfo_initsize
=
1251 __ATTR(initsize
, 0444, show_initsize
, NULL
);
1253 static ssize_t
show_taint(struct module_attribute
*mattr
,
1254 struct module_kobject
*mk
, char *buffer
)
1258 l
= module_flags_taint(mk
->mod
, buffer
);
1263 static struct module_attribute modinfo_taint
=
1264 __ATTR(taint
, 0444, show_taint
, NULL
);
1266 static struct module_attribute
*modinfo_attrs
[] = {
1269 &modinfo_srcversion
,
1274 #ifdef CONFIG_MODULE_UNLOAD
1280 static const char vermagic
[] = VERMAGIC_STRING
;
1282 static int try_to_force_load(struct module
*mod
, const char *reason
)
1284 #ifdef CONFIG_MODULE_FORCE_LOAD
1285 if (!test_taint(TAINT_FORCED_MODULE
))
1286 pr_warn("%s: %s: kernel tainted.\n", mod
->name
, reason
);
1287 add_taint_module(mod
, TAINT_FORCED_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
1294 #ifdef CONFIG_MODVERSIONS
1296 static u32
resolve_rel_crc(const s32
*crc
)
1298 return *(u32
*)((void *)crc
+ *crc
);
1301 static int check_version(const struct load_info
*info
,
1302 const char *symname
,
1306 Elf_Shdr
*sechdrs
= info
->sechdrs
;
1307 unsigned int versindex
= info
->index
.vers
;
1308 unsigned int i
, num_versions
;
1309 struct modversion_info
*versions
;
1311 /* Exporting module didn't supply crcs? OK, we're already tainted. */
1315 /* No versions at all? modprobe --force does this. */
1317 return try_to_force_load(mod
, symname
) == 0;
1319 versions
= (void *) sechdrs
[versindex
].sh_addr
;
1320 num_versions
= sechdrs
[versindex
].sh_size
1321 / sizeof(struct modversion_info
);
1323 for (i
= 0; i
< num_versions
; i
++) {
1326 if (strcmp(versions
[i
].name
, symname
) != 0)
1329 if (IS_ENABLED(CONFIG_MODULE_REL_CRCS
))
1330 crcval
= resolve_rel_crc(crc
);
1333 if (versions
[i
].crc
== crcval
)
1335 pr_debug("Found checksum %X vs module %lX\n",
1336 crcval
, versions
[i
].crc
);
1340 /* Broken toolchain. Warn once, then let it go.. */
1341 pr_warn_once("%s: no symbol version for %s\n", info
->name
, symname
);
1345 pr_warn("%s: disagrees about version of symbol %s\n",
1346 info
->name
, symname
);
1350 static inline int check_modstruct_version(const struct load_info
*info
,
1356 * Since this should be found in kernel (which can't be removed), no
1357 * locking is necessary -- use preempt_disable() to placate lockdep.
1360 if (!find_symbol("module_layout", NULL
, &crc
, NULL
, true, false)) {
1365 return check_version(info
, "module_layout", mod
, crc
);
1368 /* First part is kernel version, which we ignore if module has crcs. */
1369 static inline int same_magic(const char *amagic
, const char *bmagic
,
1373 amagic
+= strcspn(amagic
, " ");
1374 bmagic
+= strcspn(bmagic
, " ");
1376 return strcmp(amagic
, bmagic
) == 0;
1379 static inline int check_version(const struct load_info
*info
,
1380 const char *symname
,
1387 static inline int check_modstruct_version(const struct load_info
*info
,
1393 static inline int same_magic(const char *amagic
, const char *bmagic
,
1396 return strcmp(amagic
, bmagic
) == 0;
1398 #endif /* CONFIG_MODVERSIONS */
1400 static char *get_modinfo(const struct load_info
*info
, const char *tag
);
1401 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
1404 static int verify_namespace_is_imported(const struct load_info
*info
,
1405 const struct kernel_symbol
*sym
,
1408 const char *namespace;
1409 char *imported_namespace
;
1411 namespace = kernel_symbol_namespace(sym
);
1412 if (namespace && namespace[0]) {
1413 imported_namespace
= get_modinfo(info
, "import_ns");
1414 while (imported_namespace
) {
1415 if (strcmp(namespace, imported_namespace
) == 0)
1417 imported_namespace
= get_next_modinfo(
1418 info
, "import_ns", imported_namespace
);
1420 #ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1425 "%s: module uses symbol (%s) from namespace %s, but does not import it.\n",
1426 mod
->name
, kernel_symbol_name(sym
), namespace);
1427 #ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS
1434 static bool inherit_taint(struct module
*mod
, struct module
*owner
)
1436 if (!owner
|| !test_bit(TAINT_PROPRIETARY_MODULE
, &owner
->taints
))
1439 if (mod
->using_gplonly_symbols
) {
1440 pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n",
1441 mod
->name
, owner
->name
);
1445 if (!test_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
)) {
1446 pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n",
1447 mod
->name
, owner
->name
);
1448 set_bit(TAINT_PROPRIETARY_MODULE
, &mod
->taints
);
1453 /* Resolve a symbol for this module. I.e. if we find one, record usage. */
1454 static const struct kernel_symbol
*resolve_symbol(struct module
*mod
,
1455 const struct load_info
*info
,
1459 struct module
*owner
;
1460 const struct kernel_symbol
*sym
;
1462 enum mod_license license
;
1466 * The module_mutex should not be a heavily contended lock;
1467 * if we get the occasional sleep here, we'll go an extra iteration
1468 * in the wait_event_interruptible(), which is harmless.
1470 sched_annotate_sleep();
1471 mutex_lock(&module_mutex
);
1472 sym
= find_symbol(name
, &owner
, &crc
, &license
,
1473 !(mod
->taints
& (1 << TAINT_PROPRIETARY_MODULE
)), true);
1477 if (license
== GPL_ONLY
)
1478 mod
->using_gplonly_symbols
= true;
1480 if (!inherit_taint(mod
, owner
)) {
1485 if (!check_version(info
, name
, mod
, crc
)) {
1486 sym
= ERR_PTR(-EINVAL
);
1490 err
= verify_namespace_is_imported(info
, sym
, mod
);
1496 err
= ref_module(mod
, owner
);
1503 /* We must make copy under the lock if we failed to get ref. */
1504 strncpy(ownername
, module_name(owner
), MODULE_NAME_LEN
);
1506 mutex_unlock(&module_mutex
);
1510 static const struct kernel_symbol
*
1511 resolve_symbol_wait(struct module
*mod
,
1512 const struct load_info
*info
,
1515 const struct kernel_symbol
*ksym
;
1516 char owner
[MODULE_NAME_LEN
];
1518 if (wait_event_interruptible_timeout(module_wq
,
1519 !IS_ERR(ksym
= resolve_symbol(mod
, info
, name
, owner
))
1520 || PTR_ERR(ksym
) != -EBUSY
,
1522 pr_warn("%s: gave up waiting for init of module %s.\n",
1529 * /sys/module/foo/sections stuff
1530 * J. Corbet <corbet@lwn.net>
1534 #ifdef CONFIG_KALLSYMS
1535 static inline bool sect_empty(const Elf_Shdr
*sect
)
1537 return !(sect
->sh_flags
& SHF_ALLOC
) || sect
->sh_size
== 0;
1540 struct module_sect_attr
{
1541 struct bin_attribute battr
;
1542 unsigned long address
;
1545 struct module_sect_attrs
{
1546 struct attribute_group grp
;
1547 unsigned int nsections
;
1548 struct module_sect_attr attrs
[];
1551 #define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
1552 static ssize_t
module_sect_read(struct file
*file
, struct kobject
*kobj
,
1553 struct bin_attribute
*battr
,
1554 char *buf
, loff_t pos
, size_t count
)
1556 struct module_sect_attr
*sattr
=
1557 container_of(battr
, struct module_sect_attr
, battr
);
1558 char bounce
[MODULE_SECT_READ_SIZE
+ 1];
1565 * Since we're a binary read handler, we must account for the
1566 * trailing NUL byte that sprintf will write: if "buf" is
1567 * too small to hold the NUL, or the NUL is exactly the last
1568 * byte, the read will look like it got truncated by one byte.
1569 * Since there is no way to ask sprintf nicely to not write
1570 * the NUL, we have to use a bounce buffer.
1572 wrote
= scnprintf(bounce
, sizeof(bounce
), "0x%px\n",
1573 kallsyms_show_value(file
->f_cred
)
1574 ? (void *)sattr
->address
: NULL
);
1575 count
= min(count
, wrote
);
1576 memcpy(buf
, bounce
, count
);
1581 static void free_sect_attrs(struct module_sect_attrs
*sect_attrs
)
1583 unsigned int section
;
1585 for (section
= 0; section
< sect_attrs
->nsections
; section
++)
1586 kfree(sect_attrs
->attrs
[section
].battr
.attr
.name
);
1590 static void add_sect_attrs(struct module
*mod
, const struct load_info
*info
)
1592 unsigned int nloaded
= 0, i
, size
[2];
1593 struct module_sect_attrs
*sect_attrs
;
1594 struct module_sect_attr
*sattr
;
1595 struct bin_attribute
**gattr
;
1597 /* Count loaded sections and allocate structures */
1598 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1599 if (!sect_empty(&info
->sechdrs
[i
]))
1601 size
[0] = ALIGN(struct_size(sect_attrs
, attrs
, nloaded
),
1602 sizeof(sect_attrs
->grp
.bin_attrs
[0]));
1603 size
[1] = (nloaded
+ 1) * sizeof(sect_attrs
->grp
.bin_attrs
[0]);
1604 sect_attrs
= kzalloc(size
[0] + size
[1], GFP_KERNEL
);
1605 if (sect_attrs
== NULL
)
1608 /* Setup section attributes. */
1609 sect_attrs
->grp
.name
= "sections";
1610 sect_attrs
->grp
.bin_attrs
= (void *)sect_attrs
+ size
[0];
1612 sect_attrs
->nsections
= 0;
1613 sattr
= §_attrs
->attrs
[0];
1614 gattr
= §_attrs
->grp
.bin_attrs
[0];
1615 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
1616 Elf_Shdr
*sec
= &info
->sechdrs
[i
];
1617 if (sect_empty(sec
))
1619 sysfs_bin_attr_init(&sattr
->battr
);
1620 sattr
->address
= sec
->sh_addr
;
1621 sattr
->battr
.attr
.name
=
1622 kstrdup(info
->secstrings
+ sec
->sh_name
, GFP_KERNEL
);
1623 if (sattr
->battr
.attr
.name
== NULL
)
1625 sect_attrs
->nsections
++;
1626 sattr
->battr
.read
= module_sect_read
;
1627 sattr
->battr
.size
= MODULE_SECT_READ_SIZE
;
1628 sattr
->battr
.attr
.mode
= 0400;
1629 *(gattr
++) = &(sattr
++)->battr
;
1633 if (sysfs_create_group(&mod
->mkobj
.kobj
, §_attrs
->grp
))
1636 mod
->sect_attrs
= sect_attrs
;
1639 free_sect_attrs(sect_attrs
);
1642 static void remove_sect_attrs(struct module
*mod
)
1644 if (mod
->sect_attrs
) {
1645 sysfs_remove_group(&mod
->mkobj
.kobj
,
1646 &mod
->sect_attrs
->grp
);
1647 /* We are positive that no one is using any sect attrs
1648 * at this point. Deallocate immediately. */
1649 free_sect_attrs(mod
->sect_attrs
);
1650 mod
->sect_attrs
= NULL
;
1655 * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
1658 struct module_notes_attrs
{
1659 struct kobject
*dir
;
1661 struct bin_attribute attrs
[];
1664 static ssize_t
module_notes_read(struct file
*filp
, struct kobject
*kobj
,
1665 struct bin_attribute
*bin_attr
,
1666 char *buf
, loff_t pos
, size_t count
)
1669 * The caller checked the pos and count against our size.
1671 memcpy(buf
, bin_attr
->private + pos
, count
);
1675 static void free_notes_attrs(struct module_notes_attrs
*notes_attrs
,
1678 if (notes_attrs
->dir
) {
1680 sysfs_remove_bin_file(notes_attrs
->dir
,
1681 ¬es_attrs
->attrs
[i
]);
1682 kobject_put(notes_attrs
->dir
);
1687 static void add_notes_attrs(struct module
*mod
, const struct load_info
*info
)
1689 unsigned int notes
, loaded
, i
;
1690 struct module_notes_attrs
*notes_attrs
;
1691 struct bin_attribute
*nattr
;
1693 /* failed to create section attributes, so can't create notes */
1694 if (!mod
->sect_attrs
)
1697 /* Count notes sections and allocate structures. */
1699 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
1700 if (!sect_empty(&info
->sechdrs
[i
]) &&
1701 (info
->sechdrs
[i
].sh_type
== SHT_NOTE
))
1707 notes_attrs
= kzalloc(struct_size(notes_attrs
, attrs
, notes
),
1709 if (notes_attrs
== NULL
)
1712 notes_attrs
->notes
= notes
;
1713 nattr
= ¬es_attrs
->attrs
[0];
1714 for (loaded
= i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
1715 if (sect_empty(&info
->sechdrs
[i
]))
1717 if (info
->sechdrs
[i
].sh_type
== SHT_NOTE
) {
1718 sysfs_bin_attr_init(nattr
);
1719 nattr
->attr
.name
= mod
->sect_attrs
->attrs
[loaded
].battr
.attr
.name
;
1720 nattr
->attr
.mode
= S_IRUGO
;
1721 nattr
->size
= info
->sechdrs
[i
].sh_size
;
1722 nattr
->private = (void *) info
->sechdrs
[i
].sh_addr
;
1723 nattr
->read
= module_notes_read
;
1729 notes_attrs
->dir
= kobject_create_and_add("notes", &mod
->mkobj
.kobj
);
1730 if (!notes_attrs
->dir
)
1733 for (i
= 0; i
< notes
; ++i
)
1734 if (sysfs_create_bin_file(notes_attrs
->dir
,
1735 ¬es_attrs
->attrs
[i
]))
1738 mod
->notes_attrs
= notes_attrs
;
1742 free_notes_attrs(notes_attrs
, i
);
1745 static void remove_notes_attrs(struct module
*mod
)
1747 if (mod
->notes_attrs
)
1748 free_notes_attrs(mod
->notes_attrs
, mod
->notes_attrs
->notes
);
1753 static inline void add_sect_attrs(struct module
*mod
,
1754 const struct load_info
*info
)
1758 static inline void remove_sect_attrs(struct module
*mod
)
1762 static inline void add_notes_attrs(struct module
*mod
,
1763 const struct load_info
*info
)
1767 static inline void remove_notes_attrs(struct module
*mod
)
1770 #endif /* CONFIG_KALLSYMS */
1772 static void del_usage_links(struct module
*mod
)
1774 #ifdef CONFIG_MODULE_UNLOAD
1775 struct module_use
*use
;
1777 mutex_lock(&module_mutex
);
1778 list_for_each_entry(use
, &mod
->target_list
, target_list
)
1779 sysfs_remove_link(use
->target
->holders_dir
, mod
->name
);
1780 mutex_unlock(&module_mutex
);
1784 static int add_usage_links(struct module
*mod
)
1787 #ifdef CONFIG_MODULE_UNLOAD
1788 struct module_use
*use
;
1790 mutex_lock(&module_mutex
);
1791 list_for_each_entry(use
, &mod
->target_list
, target_list
) {
1792 ret
= sysfs_create_link(use
->target
->holders_dir
,
1793 &mod
->mkobj
.kobj
, mod
->name
);
1797 mutex_unlock(&module_mutex
);
1799 del_usage_links(mod
);
1804 static void module_remove_modinfo_attrs(struct module
*mod
, int end
);
1806 static int module_add_modinfo_attrs(struct module
*mod
)
1808 struct module_attribute
*attr
;
1809 struct module_attribute
*temp_attr
;
1813 mod
->modinfo_attrs
= kzalloc((sizeof(struct module_attribute
) *
1814 (ARRAY_SIZE(modinfo_attrs
) + 1)),
1816 if (!mod
->modinfo_attrs
)
1819 temp_attr
= mod
->modinfo_attrs
;
1820 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
1821 if (!attr
->test
|| attr
->test(mod
)) {
1822 memcpy(temp_attr
, attr
, sizeof(*temp_attr
));
1823 sysfs_attr_init(&temp_attr
->attr
);
1824 error
= sysfs_create_file(&mod
->mkobj
.kobj
,
1836 module_remove_modinfo_attrs(mod
, --i
);
1838 kfree(mod
->modinfo_attrs
);
1842 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1844 struct module_attribute
*attr
;
1847 for (i
= 0; (attr
= &mod
->modinfo_attrs
[i
]); i
++) {
1848 if (end
>= 0 && i
> end
)
1850 /* pick a field to test for end of list */
1851 if (!attr
->attr
.name
)
1853 sysfs_remove_file(&mod
->mkobj
.kobj
, &attr
->attr
);
1857 kfree(mod
->modinfo_attrs
);
1860 static void mod_kobject_put(struct module
*mod
)
1862 DECLARE_COMPLETION_ONSTACK(c
);
1863 mod
->mkobj
.kobj_completion
= &c
;
1864 kobject_put(&mod
->mkobj
.kobj
);
1865 wait_for_completion(&c
);
1868 static int mod_sysfs_init(struct module
*mod
)
1871 struct kobject
*kobj
;
1873 if (!module_sysfs_initialized
) {
1874 pr_err("%s: module sysfs not initialized\n", mod
->name
);
1879 kobj
= kset_find_obj(module_kset
, mod
->name
);
1881 pr_err("%s: module is already loaded\n", mod
->name
);
1887 mod
->mkobj
.mod
= mod
;
1889 memset(&mod
->mkobj
.kobj
, 0, sizeof(mod
->mkobj
.kobj
));
1890 mod
->mkobj
.kobj
.kset
= module_kset
;
1891 err
= kobject_init_and_add(&mod
->mkobj
.kobj
, &module_ktype
, NULL
,
1894 mod_kobject_put(mod
);
1896 /* delay uevent until full sysfs population */
1901 static int mod_sysfs_setup(struct module
*mod
,
1902 const struct load_info
*info
,
1903 struct kernel_param
*kparam
,
1904 unsigned int num_params
)
1908 err
= mod_sysfs_init(mod
);
1912 mod
->holders_dir
= kobject_create_and_add("holders", &mod
->mkobj
.kobj
);
1913 if (!mod
->holders_dir
) {
1918 err
= module_param_sysfs_setup(mod
, kparam
, num_params
);
1920 goto out_unreg_holders
;
1922 err
= module_add_modinfo_attrs(mod
);
1924 goto out_unreg_param
;
1926 err
= add_usage_links(mod
);
1928 goto out_unreg_modinfo_attrs
;
1930 add_sect_attrs(mod
, info
);
1931 add_notes_attrs(mod
, info
);
1933 kobject_uevent(&mod
->mkobj
.kobj
, KOBJ_ADD
);
1936 out_unreg_modinfo_attrs
:
1937 module_remove_modinfo_attrs(mod
, -1);
1939 module_param_sysfs_remove(mod
);
1941 kobject_put(mod
->holders_dir
);
1943 mod_kobject_put(mod
);
1948 static void mod_sysfs_fini(struct module
*mod
)
1950 remove_notes_attrs(mod
);
1951 remove_sect_attrs(mod
);
1952 mod_kobject_put(mod
);
1955 static void init_param_lock(struct module
*mod
)
1957 mutex_init(&mod
->param_lock
);
1959 #else /* !CONFIG_SYSFS */
1961 static int mod_sysfs_setup(struct module
*mod
,
1962 const struct load_info
*info
,
1963 struct kernel_param
*kparam
,
1964 unsigned int num_params
)
1969 static void mod_sysfs_fini(struct module
*mod
)
1973 static void module_remove_modinfo_attrs(struct module
*mod
, int end
)
1977 static void del_usage_links(struct module
*mod
)
1981 static void init_param_lock(struct module
*mod
)
1984 #endif /* CONFIG_SYSFS */
1986 static void mod_sysfs_teardown(struct module
*mod
)
1988 del_usage_links(mod
);
1989 module_remove_modinfo_attrs(mod
, -1);
1990 module_param_sysfs_remove(mod
);
1991 kobject_put(mod
->mkobj
.drivers_dir
);
1992 kobject_put(mod
->holders_dir
);
1993 mod_sysfs_fini(mod
);
1997 * LKM RO/NX protection: protect module's text/ro-data
1998 * from modification and any data from execution.
2000 * General layout of module is:
2001 * [text] [read-only-data] [ro-after-init] [writable data]
2002 * text_size -----^ ^ ^ ^
2003 * ro_size ------------------------| | |
2004 * ro_after_init_size -----------------------------| |
2005 * size -----------------------------------------------------------|
2007 * These values are always page-aligned (as is base)
2011 * Since some arches are moving towards PAGE_KERNEL module allocations instead
2012 * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the
2013 * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of
2014 * whether we are strict.
2016 #ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
2017 static void frob_text(const struct module_layout
*layout
,
2018 int (*set_memory
)(unsigned long start
, int num_pages
))
2020 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2021 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
2022 set_memory((unsigned long)layout
->base
,
2023 layout
->text_size
>> PAGE_SHIFT
);
2026 static void module_enable_x(const struct module
*mod
)
2028 frob_text(&mod
->core_layout
, set_memory_x
);
2029 frob_text(&mod
->init_layout
, set_memory_x
);
2031 #else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2032 static void module_enable_x(const struct module
*mod
) { }
2033 #endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
2035 #ifdef CONFIG_STRICT_MODULE_RWX
2036 static void frob_rodata(const struct module_layout
*layout
,
2037 int (*set_memory
)(unsigned long start
, int num_pages
))
2039 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2040 BUG_ON((unsigned long)layout
->text_size
& (PAGE_SIZE
-1));
2041 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
2042 set_memory((unsigned long)layout
->base
+ layout
->text_size
,
2043 (layout
->ro_size
- layout
->text_size
) >> PAGE_SHIFT
);
2046 static void frob_ro_after_init(const struct module_layout
*layout
,
2047 int (*set_memory
)(unsigned long start
, int num_pages
))
2049 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2050 BUG_ON((unsigned long)layout
->ro_size
& (PAGE_SIZE
-1));
2051 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
2052 set_memory((unsigned long)layout
->base
+ layout
->ro_size
,
2053 (layout
->ro_after_init_size
- layout
->ro_size
) >> PAGE_SHIFT
);
2056 static void frob_writable_data(const struct module_layout
*layout
,
2057 int (*set_memory
)(unsigned long start
, int num_pages
))
2059 BUG_ON((unsigned long)layout
->base
& (PAGE_SIZE
-1));
2060 BUG_ON((unsigned long)layout
->ro_after_init_size
& (PAGE_SIZE
-1));
2061 BUG_ON((unsigned long)layout
->size
& (PAGE_SIZE
-1));
2062 set_memory((unsigned long)layout
->base
+ layout
->ro_after_init_size
,
2063 (layout
->size
- layout
->ro_after_init_size
) >> PAGE_SHIFT
);
2066 static void module_enable_ro(const struct module
*mod
, bool after_init
)
2068 if (!rodata_enabled
)
2071 set_vm_flush_reset_perms(mod
->core_layout
.base
);
2072 set_vm_flush_reset_perms(mod
->init_layout
.base
);
2073 frob_text(&mod
->core_layout
, set_memory_ro
);
2075 frob_rodata(&mod
->core_layout
, set_memory_ro
);
2076 frob_text(&mod
->init_layout
, set_memory_ro
);
2077 frob_rodata(&mod
->init_layout
, set_memory_ro
);
2080 frob_ro_after_init(&mod
->core_layout
, set_memory_ro
);
2083 static void module_enable_nx(const struct module
*mod
)
2085 frob_rodata(&mod
->core_layout
, set_memory_nx
);
2086 frob_ro_after_init(&mod
->core_layout
, set_memory_nx
);
2087 frob_writable_data(&mod
->core_layout
, set_memory_nx
);
2088 frob_rodata(&mod
->init_layout
, set_memory_nx
);
2089 frob_writable_data(&mod
->init_layout
, set_memory_nx
);
2092 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2093 char *secstrings
, struct module
*mod
)
2095 const unsigned long shf_wx
= SHF_WRITE
|SHF_EXECINSTR
;
2098 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
2099 if ((sechdrs
[i
].sh_flags
& shf_wx
) == shf_wx
)
2106 #else /* !CONFIG_STRICT_MODULE_RWX */
2107 static void module_enable_nx(const struct module
*mod
) { }
2108 static void module_enable_ro(const struct module
*mod
, bool after_init
) {}
2109 static int module_enforce_rwx_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
2110 char *secstrings
, struct module
*mod
)
2114 #endif /* CONFIG_STRICT_MODULE_RWX */
2116 #ifdef CONFIG_LIVEPATCH
2118 * Persist Elf information about a module. Copy the Elf header,
2119 * section header table, section string table, and symtab section
2120 * index from info to mod->klp_info.
2122 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2124 unsigned int size
, symndx
;
2127 size
= sizeof(*mod
->klp_info
);
2128 mod
->klp_info
= kmalloc(size
, GFP_KERNEL
);
2129 if (mod
->klp_info
== NULL
)
2133 size
= sizeof(mod
->klp_info
->hdr
);
2134 memcpy(&mod
->klp_info
->hdr
, info
->hdr
, size
);
2136 /* Elf section header table */
2137 size
= sizeof(*info
->sechdrs
) * info
->hdr
->e_shnum
;
2138 mod
->klp_info
->sechdrs
= kmemdup(info
->sechdrs
, size
, GFP_KERNEL
);
2139 if (mod
->klp_info
->sechdrs
== NULL
) {
2144 /* Elf section name string table */
2145 size
= info
->sechdrs
[info
->hdr
->e_shstrndx
].sh_size
;
2146 mod
->klp_info
->secstrings
= kmemdup(info
->secstrings
, size
, GFP_KERNEL
);
2147 if (mod
->klp_info
->secstrings
== NULL
) {
2152 /* Elf symbol section index */
2153 symndx
= info
->index
.sym
;
2154 mod
->klp_info
->symndx
= symndx
;
2157 * For livepatch modules, core_kallsyms.symtab is a complete
2158 * copy of the original symbol table. Adjust sh_addr to point
2159 * to core_kallsyms.symtab since the copy of the symtab in module
2160 * init memory is freed at the end of do_init_module().
2162 mod
->klp_info
->sechdrs
[symndx
].sh_addr
= \
2163 (unsigned long) mod
->core_kallsyms
.symtab
;
2168 kfree(mod
->klp_info
->sechdrs
);
2170 kfree(mod
->klp_info
);
2174 static void free_module_elf(struct module
*mod
)
2176 kfree(mod
->klp_info
->sechdrs
);
2177 kfree(mod
->klp_info
->secstrings
);
2178 kfree(mod
->klp_info
);
2180 #else /* !CONFIG_LIVEPATCH */
2181 static int copy_module_elf(struct module
*mod
, struct load_info
*info
)
2186 static void free_module_elf(struct module
*mod
)
2189 #endif /* CONFIG_LIVEPATCH */
2191 void __weak
module_memfree(void *module_region
)
2194 * This memory may be RO, and freeing RO memory in an interrupt is not
2195 * supported by vmalloc.
2197 WARN_ON(in_interrupt());
2198 vfree(module_region
);
2201 void __weak
module_arch_cleanup(struct module
*mod
)
2205 void __weak
module_arch_freeing_init(struct module
*mod
)
2209 /* Free a module, remove from lists, etc. */
2210 static void free_module(struct module
*mod
)
2212 trace_module_free(mod
);
2214 mod_sysfs_teardown(mod
);
2216 /* We leave it in list to prevent duplicate loads, but make sure
2217 * that noone uses it while it's being deconstructed. */
2218 mutex_lock(&module_mutex
);
2219 mod
->state
= MODULE_STATE_UNFORMED
;
2220 mutex_unlock(&module_mutex
);
2222 /* Remove dynamic debug info */
2223 ddebug_remove_module(mod
->name
);
2225 /* Arch-specific cleanup. */
2226 module_arch_cleanup(mod
);
2228 /* Module unload stuff */
2229 module_unload_free(mod
);
2231 /* Free any allocated parameters. */
2232 destroy_params(mod
->kp
, mod
->num_kp
);
2234 if (is_livepatch_module(mod
))
2235 free_module_elf(mod
);
2237 /* Now we can delete it from the lists */
2238 mutex_lock(&module_mutex
);
2239 /* Unlink carefully: kallsyms could be walking list. */
2240 list_del_rcu(&mod
->list
);
2241 mod_tree_remove(mod
);
2242 /* Remove this module from bug list, this uses list_del_rcu */
2243 module_bug_cleanup(mod
);
2244 /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */
2246 mutex_unlock(&module_mutex
);
2248 /* This may be empty, but that's OK */
2249 module_arch_freeing_init(mod
);
2250 module_memfree(mod
->init_layout
.base
);
2252 percpu_modfree(mod
);
2254 /* Free lock-classes; relies on the preceding sync_rcu(). */
2255 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
2257 /* Finally, free the core (containing the module structure) */
2258 module_memfree(mod
->core_layout
.base
);
2261 void *__symbol_get(const char *symbol
)
2263 struct module
*owner
;
2264 const struct kernel_symbol
*sym
;
2267 sym
= find_symbol(symbol
, &owner
, NULL
, NULL
, true, true);
2268 if (sym
&& strong_try_module_get(owner
))
2272 return sym
? (void *)kernel_symbol_value(sym
) : NULL
;
2274 EXPORT_SYMBOL_GPL(__symbol_get
);
2277 * Ensure that an exported symbol [global namespace] does not already exist
2278 * in the kernel or in some other module's exported symbol table.
2280 * You must hold the module_mutex.
2282 static int verify_exported_symbols(struct module
*mod
)
2285 struct module
*owner
;
2286 const struct kernel_symbol
*s
;
2288 const struct kernel_symbol
*sym
;
2291 { mod
->syms
, mod
->num_syms
},
2292 { mod
->gpl_syms
, mod
->num_gpl_syms
},
2293 { mod
->gpl_future_syms
, mod
->num_gpl_future_syms
},
2294 #ifdef CONFIG_UNUSED_SYMBOLS
2295 { mod
->unused_syms
, mod
->num_unused_syms
},
2296 { mod
->unused_gpl_syms
, mod
->num_unused_gpl_syms
},
2300 for (i
= 0; i
< ARRAY_SIZE(arr
); i
++) {
2301 for (s
= arr
[i
].sym
; s
< arr
[i
].sym
+ arr
[i
].num
; s
++) {
2302 if (find_symbol(kernel_symbol_name(s
), &owner
, NULL
,
2303 NULL
, true, false)) {
2304 pr_err("%s: exports duplicate symbol %s"
2306 mod
->name
, kernel_symbol_name(s
),
2307 module_name(owner
));
2315 /* Change all symbols so that st_value encodes the pointer directly. */
2316 static int simplify_symbols(struct module
*mod
, const struct load_info
*info
)
2318 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2319 Elf_Sym
*sym
= (void *)symsec
->sh_addr
;
2320 unsigned long secbase
;
2323 const struct kernel_symbol
*ksym
;
2325 for (i
= 1; i
< symsec
->sh_size
/ sizeof(Elf_Sym
); i
++) {
2326 const char *name
= info
->strtab
+ sym
[i
].st_name
;
2328 switch (sym
[i
].st_shndx
) {
2330 /* Ignore common symbols */
2331 if (!strncmp(name
, "__gnu_lto", 9))
2334 /* We compiled with -fno-common. These are not
2335 supposed to happen. */
2336 pr_debug("Common symbol: %s\n", name
);
2337 pr_warn("%s: please compile with -fno-common\n",
2343 /* Don't need to do anything */
2344 pr_debug("Absolute symbol: 0x%08lx\n",
2345 (long)sym
[i
].st_value
);
2349 /* Livepatch symbols are resolved by livepatch */
2353 ksym
= resolve_symbol_wait(mod
, info
, name
);
2354 /* Ok if resolved. */
2355 if (ksym
&& !IS_ERR(ksym
)) {
2356 sym
[i
].st_value
= kernel_symbol_value(ksym
);
2361 if (!ksym
&& ELF_ST_BIND(sym
[i
].st_info
) == STB_WEAK
)
2364 ret
= PTR_ERR(ksym
) ?: -ENOENT
;
2365 pr_warn("%s: Unknown symbol %s (err %d)\n",
2366 mod
->name
, name
, ret
);
2370 /* Divert to percpu allocation if a percpu var. */
2371 if (sym
[i
].st_shndx
== info
->index
.pcpu
)
2372 secbase
= (unsigned long)mod_percpu(mod
);
2374 secbase
= info
->sechdrs
[sym
[i
].st_shndx
].sh_addr
;
2375 sym
[i
].st_value
+= secbase
;
2383 static int apply_relocations(struct module
*mod
, const struct load_info
*info
)
2388 /* Now do relocations. */
2389 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2390 unsigned int infosec
= info
->sechdrs
[i
].sh_info
;
2392 /* Not a valid relocation section? */
2393 if (infosec
>= info
->hdr
->e_shnum
)
2396 /* Don't bother with non-allocated sections */
2397 if (!(info
->sechdrs
[infosec
].sh_flags
& SHF_ALLOC
))
2400 if (info
->sechdrs
[i
].sh_flags
& SHF_RELA_LIVEPATCH
)
2401 err
= klp_apply_section_relocs(mod
, info
->sechdrs
,
2406 else if (info
->sechdrs
[i
].sh_type
== SHT_REL
)
2407 err
= apply_relocate(info
->sechdrs
, info
->strtab
,
2408 info
->index
.sym
, i
, mod
);
2409 else if (info
->sechdrs
[i
].sh_type
== SHT_RELA
)
2410 err
= apply_relocate_add(info
->sechdrs
, info
->strtab
,
2411 info
->index
.sym
, i
, mod
);
2418 /* Additional bytes needed by arch in front of individual sections */
2419 unsigned int __weak
arch_mod_section_prepend(struct module
*mod
,
2420 unsigned int section
)
2422 /* default implementation just returns zero */
2426 /* Update size with this section: return offset. */
2427 static long get_offset(struct module
*mod
, unsigned int *size
,
2428 Elf_Shdr
*sechdr
, unsigned int section
)
2432 *size
+= arch_mod_section_prepend(mod
, section
);
2433 ret
= ALIGN(*size
, sechdr
->sh_addralign
?: 1);
2434 *size
= ret
+ sechdr
->sh_size
;
2438 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
2439 might -- code, read-only data, read-write data, small data. Tally
2440 sizes, and place the offsets into sh_entsize fields: high bit means it
2442 static void layout_sections(struct module
*mod
, struct load_info
*info
)
2444 static unsigned long const masks
[][2] = {
2445 /* NOTE: all executable code must be the first section
2446 * in this array; otherwise modify the text_size
2447 * finder in the two loops below */
2448 { SHF_EXECINSTR
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2449 { SHF_ALLOC
, SHF_WRITE
| ARCH_SHF_SMALL
},
2450 { SHF_RO_AFTER_INIT
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2451 { SHF_WRITE
| SHF_ALLOC
, ARCH_SHF_SMALL
},
2452 { ARCH_SHF_SMALL
| SHF_ALLOC
, 0 }
2456 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++)
2457 info
->sechdrs
[i
].sh_entsize
= ~0UL;
2459 pr_debug("Core section allocation order:\n");
2460 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2461 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2462 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2463 const char *sname
= info
->secstrings
+ s
->sh_name
;
2465 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2466 || (s
->sh_flags
& masks
[m
][1])
2467 || s
->sh_entsize
!= ~0UL
2468 || module_init_section(sname
))
2470 s
->sh_entsize
= get_offset(mod
, &mod
->core_layout
.size
, s
, i
);
2471 pr_debug("\t%s\n", sname
);
2474 case 0: /* executable */
2475 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2476 mod
->core_layout
.text_size
= mod
->core_layout
.size
;
2478 case 1: /* RO: text and ro-data */
2479 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2480 mod
->core_layout
.ro_size
= mod
->core_layout
.size
;
2482 case 2: /* RO after init */
2483 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2484 mod
->core_layout
.ro_after_init_size
= mod
->core_layout
.size
;
2486 case 4: /* whole core */
2487 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2492 pr_debug("Init section allocation order:\n");
2493 for (m
= 0; m
< ARRAY_SIZE(masks
); ++m
) {
2494 for (i
= 0; i
< info
->hdr
->e_shnum
; ++i
) {
2495 Elf_Shdr
*s
= &info
->sechdrs
[i
];
2496 const char *sname
= info
->secstrings
+ s
->sh_name
;
2498 if ((s
->sh_flags
& masks
[m
][0]) != masks
[m
][0]
2499 || (s
->sh_flags
& masks
[m
][1])
2500 || s
->sh_entsize
!= ~0UL
2501 || !module_init_section(sname
))
2503 s
->sh_entsize
= (get_offset(mod
, &mod
->init_layout
.size
, s
, i
)
2504 | INIT_OFFSET_MASK
);
2505 pr_debug("\t%s\n", sname
);
2508 case 0: /* executable */
2509 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2510 mod
->init_layout
.text_size
= mod
->init_layout
.size
;
2512 case 1: /* RO: text and ro-data */
2513 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2514 mod
->init_layout
.ro_size
= mod
->init_layout
.size
;
2518 * RO after init doesn't apply to init_layout (only
2519 * core_layout), so it just takes the value of ro_size.
2521 mod
->init_layout
.ro_after_init_size
= mod
->init_layout
.ro_size
;
2523 case 4: /* whole init */
2524 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2530 static void set_license(struct module
*mod
, const char *license
)
2533 license
= "unspecified";
2535 if (!license_is_gpl_compatible(license
)) {
2536 if (!test_taint(TAINT_PROPRIETARY_MODULE
))
2537 pr_warn("%s: module license '%s' taints kernel.\n",
2538 mod
->name
, license
);
2539 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
2540 LOCKDEP_NOW_UNRELIABLE
);
2544 /* Parse tag=value strings from .modinfo section */
2545 static char *next_string(char *string
, unsigned long *secsize
)
2547 /* Skip non-zero chars */
2550 if ((*secsize
)-- <= 1)
2554 /* Skip any zero padding. */
2555 while (!string
[0]) {
2557 if ((*secsize
)-- <= 1)
2563 static char *get_next_modinfo(const struct load_info
*info
, const char *tag
,
2567 unsigned int taglen
= strlen(tag
);
2568 Elf_Shdr
*infosec
= &info
->sechdrs
[info
->index
.info
];
2569 unsigned long size
= infosec
->sh_size
;
2572 * get_modinfo() calls made before rewrite_section_headers()
2573 * must use sh_offset, as sh_addr isn't set!
2575 char *modinfo
= (char *)info
->hdr
+ infosec
->sh_offset
;
2578 size
-= prev
- modinfo
;
2579 modinfo
= next_string(prev
, &size
);
2582 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
2583 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
2584 return p
+ taglen
+ 1;
2589 static char *get_modinfo(const struct load_info
*info
, const char *tag
)
2591 return get_next_modinfo(info
, tag
, NULL
);
2594 static void setup_modinfo(struct module
*mod
, struct load_info
*info
)
2596 struct module_attribute
*attr
;
2599 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2601 attr
->setup(mod
, get_modinfo(info
, attr
->attr
.name
));
2605 static void free_modinfo(struct module
*mod
)
2607 struct module_attribute
*attr
;
2610 for (i
= 0; (attr
= modinfo_attrs
[i
]); i
++) {
2616 #ifdef CONFIG_KALLSYMS
2618 /* Lookup exported symbol in given range of kernel_symbols */
2619 static const struct kernel_symbol
*lookup_exported_symbol(const char *name
,
2620 const struct kernel_symbol
*start
,
2621 const struct kernel_symbol
*stop
)
2623 return bsearch(name
, start
, stop
- start
,
2624 sizeof(struct kernel_symbol
), cmp_name
);
2627 static int is_exported(const char *name
, unsigned long value
,
2628 const struct module
*mod
)
2630 const struct kernel_symbol
*ks
;
2632 ks
= lookup_exported_symbol(name
, __start___ksymtab
, __stop___ksymtab
);
2634 ks
= lookup_exported_symbol(name
, mod
->syms
, mod
->syms
+ mod
->num_syms
);
2636 return ks
!= NULL
&& kernel_symbol_value(ks
) == value
;
2640 static char elf_type(const Elf_Sym
*sym
, const struct load_info
*info
)
2642 const Elf_Shdr
*sechdrs
= info
->sechdrs
;
2644 if (ELF_ST_BIND(sym
->st_info
) == STB_WEAK
) {
2645 if (ELF_ST_TYPE(sym
->st_info
) == STT_OBJECT
)
2650 if (sym
->st_shndx
== SHN_UNDEF
)
2652 if (sym
->st_shndx
== SHN_ABS
|| sym
->st_shndx
== info
->index
.pcpu
)
2654 if (sym
->st_shndx
>= SHN_LORESERVE
)
2656 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_EXECINSTR
)
2658 if (sechdrs
[sym
->st_shndx
].sh_flags
& SHF_ALLOC
2659 && sechdrs
[sym
->st_shndx
].sh_type
!= SHT_NOBITS
) {
2660 if (!(sechdrs
[sym
->st_shndx
].sh_flags
& SHF_WRITE
))
2662 else if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2667 if (sechdrs
[sym
->st_shndx
].sh_type
== SHT_NOBITS
) {
2668 if (sechdrs
[sym
->st_shndx
].sh_flags
& ARCH_SHF_SMALL
)
2673 if (strstarts(info
->secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
,
2680 static bool is_core_symbol(const Elf_Sym
*src
, const Elf_Shdr
*sechdrs
,
2681 unsigned int shnum
, unsigned int pcpundx
)
2683 const Elf_Shdr
*sec
;
2685 if (src
->st_shndx
== SHN_UNDEF
2686 || src
->st_shndx
>= shnum
2690 #ifdef CONFIG_KALLSYMS_ALL
2691 if (src
->st_shndx
== pcpundx
)
2695 sec
= sechdrs
+ src
->st_shndx
;
2696 if (!(sec
->sh_flags
& SHF_ALLOC
)
2697 #ifndef CONFIG_KALLSYMS_ALL
2698 || !(sec
->sh_flags
& SHF_EXECINSTR
)
2700 || (sec
->sh_entsize
& INIT_OFFSET_MASK
))
2707 * We only allocate and copy the strings needed by the parts of symtab
2708 * we keep. This is simple, but has the effect of making multiple
2709 * copies of duplicates. We could be more sophisticated, see
2710 * linux-kernel thread starting with
2711 * <73defb5e4bca04a6431392cc341112b1@localhost>.
2713 static void layout_symtab(struct module
*mod
, struct load_info
*info
)
2715 Elf_Shdr
*symsect
= info
->sechdrs
+ info
->index
.sym
;
2716 Elf_Shdr
*strsect
= info
->sechdrs
+ info
->index
.str
;
2718 unsigned int i
, nsrc
, ndst
, strtab_size
= 0;
2720 /* Put symbol section at end of init part of module. */
2721 symsect
->sh_flags
|= SHF_ALLOC
;
2722 symsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, symsect
,
2723 info
->index
.sym
) | INIT_OFFSET_MASK
;
2724 pr_debug("\t%s\n", info
->secstrings
+ symsect
->sh_name
);
2726 src
= (void *)info
->hdr
+ symsect
->sh_offset
;
2727 nsrc
= symsect
->sh_size
/ sizeof(*src
);
2729 /* Compute total space required for the core symbols' strtab. */
2730 for (ndst
= i
= 0; i
< nsrc
; i
++) {
2731 if (i
== 0 || is_livepatch_module(mod
) ||
2732 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2733 info
->index
.pcpu
)) {
2734 strtab_size
+= strlen(&info
->strtab
[src
[i
].st_name
])+1;
2739 /* Append room for core symbols at end of core part. */
2740 info
->symoffs
= ALIGN(mod
->core_layout
.size
, symsect
->sh_addralign
?: 1);
2741 info
->stroffs
= mod
->core_layout
.size
= info
->symoffs
+ ndst
* sizeof(Elf_Sym
);
2742 mod
->core_layout
.size
+= strtab_size
;
2743 info
->core_typeoffs
= mod
->core_layout
.size
;
2744 mod
->core_layout
.size
+= ndst
* sizeof(char);
2745 mod
->core_layout
.size
= debug_align(mod
->core_layout
.size
);
2747 /* Put string table section at end of init part of module. */
2748 strsect
->sh_flags
|= SHF_ALLOC
;
2749 strsect
->sh_entsize
= get_offset(mod
, &mod
->init_layout
.size
, strsect
,
2750 info
->index
.str
) | INIT_OFFSET_MASK
;
2751 pr_debug("\t%s\n", info
->secstrings
+ strsect
->sh_name
);
2753 /* We'll tack temporary mod_kallsyms on the end. */
2754 mod
->init_layout
.size
= ALIGN(mod
->init_layout
.size
,
2755 __alignof__(struct mod_kallsyms
));
2756 info
->mod_kallsyms_init_off
= mod
->init_layout
.size
;
2757 mod
->init_layout
.size
+= sizeof(struct mod_kallsyms
);
2758 info
->init_typeoffs
= mod
->init_layout
.size
;
2759 mod
->init_layout
.size
+= nsrc
* sizeof(char);
2760 mod
->init_layout
.size
= debug_align(mod
->init_layout
.size
);
2764 * We use the full symtab and strtab which layout_symtab arranged to
2765 * be appended to the init section. Later we switch to the cut-down
2768 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2770 unsigned int i
, ndst
;
2774 Elf_Shdr
*symsec
= &info
->sechdrs
[info
->index
.sym
];
2776 /* Set up to point into init section. */
2777 mod
->kallsyms
= mod
->init_layout
.base
+ info
->mod_kallsyms_init_off
;
2779 mod
->kallsyms
->symtab
= (void *)symsec
->sh_addr
;
2780 mod
->kallsyms
->num_symtab
= symsec
->sh_size
/ sizeof(Elf_Sym
);
2781 /* Make sure we get permanent strtab: don't use info->strtab. */
2782 mod
->kallsyms
->strtab
= (void *)info
->sechdrs
[info
->index
.str
].sh_addr
;
2783 mod
->kallsyms
->typetab
= mod
->init_layout
.base
+ info
->init_typeoffs
;
2786 * Now populate the cut down core kallsyms for after init
2787 * and set types up while we still have access to sections.
2789 mod
->core_kallsyms
.symtab
= dst
= mod
->core_layout
.base
+ info
->symoffs
;
2790 mod
->core_kallsyms
.strtab
= s
= mod
->core_layout
.base
+ info
->stroffs
;
2791 mod
->core_kallsyms
.typetab
= mod
->core_layout
.base
+ info
->core_typeoffs
;
2792 src
= mod
->kallsyms
->symtab
;
2793 for (ndst
= i
= 0; i
< mod
->kallsyms
->num_symtab
; i
++) {
2794 mod
->kallsyms
->typetab
[i
] = elf_type(src
+ i
, info
);
2795 if (i
== 0 || is_livepatch_module(mod
) ||
2796 is_core_symbol(src
+i
, info
->sechdrs
, info
->hdr
->e_shnum
,
2797 info
->index
.pcpu
)) {
2798 mod
->core_kallsyms
.typetab
[ndst
] =
2799 mod
->kallsyms
->typetab
[i
];
2801 dst
[ndst
++].st_name
= s
- mod
->core_kallsyms
.strtab
;
2802 s
+= strlcpy(s
, &mod
->kallsyms
->strtab
[src
[i
].st_name
],
2806 mod
->core_kallsyms
.num_symtab
= ndst
;
2809 static inline void layout_symtab(struct module
*mod
, struct load_info
*info
)
2813 static void add_kallsyms(struct module
*mod
, const struct load_info
*info
)
2816 #endif /* CONFIG_KALLSYMS */
2818 static void dynamic_debug_setup(struct module
*mod
, struct _ddebug
*debug
, unsigned int num
)
2822 ddebug_add_module(debug
, num
, mod
->name
);
2825 static void dynamic_debug_remove(struct module
*mod
, struct _ddebug
*debug
)
2828 ddebug_remove_module(mod
->name
);
2831 void * __weak
module_alloc(unsigned long size
)
2833 return __vmalloc_node_range(size
, 1, VMALLOC_START
, VMALLOC_END
,
2834 GFP_KERNEL
, PAGE_KERNEL_EXEC
, VM_FLUSH_RESET_PERMS
,
2835 NUMA_NO_NODE
, __builtin_return_address(0));
2838 bool __weak
module_init_section(const char *name
)
2840 return strstarts(name
, ".init");
2843 bool __weak
module_exit_section(const char *name
)
2845 return strstarts(name
, ".exit");
2848 #ifdef CONFIG_DEBUG_KMEMLEAK
2849 static void kmemleak_load_module(const struct module
*mod
,
2850 const struct load_info
*info
)
2854 /* only scan the sections containing data */
2855 kmemleak_scan_area(mod
, sizeof(struct module
), GFP_KERNEL
);
2857 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
2858 /* Scan all writable sections that's not executable */
2859 if (!(info
->sechdrs
[i
].sh_flags
& SHF_ALLOC
) ||
2860 !(info
->sechdrs
[i
].sh_flags
& SHF_WRITE
) ||
2861 (info
->sechdrs
[i
].sh_flags
& SHF_EXECINSTR
))
2864 kmemleak_scan_area((void *)info
->sechdrs
[i
].sh_addr
,
2865 info
->sechdrs
[i
].sh_size
, GFP_KERNEL
);
2869 static inline void kmemleak_load_module(const struct module
*mod
,
2870 const struct load_info
*info
)
2875 #ifdef CONFIG_MODULE_SIG
2876 static int module_sig_check(struct load_info
*info
, int flags
)
2879 const unsigned long markerlen
= sizeof(MODULE_SIG_STRING
) - 1;
2881 const void *mod
= info
->hdr
;
2884 * Require flags == 0, as a module with version information
2885 * removed is no longer the module that was signed
2888 info
->len
> markerlen
&&
2889 memcmp(mod
+ info
->len
- markerlen
, MODULE_SIG_STRING
, markerlen
) == 0) {
2890 /* We truncate the module to discard the signature */
2891 info
->len
-= markerlen
;
2892 err
= mod_verify_sig(mod
, info
);
2897 info
->sig_ok
= true;
2900 /* We don't permit modules to be loaded into trusted kernels
2901 * without a valid signature on them, but if we're not
2902 * enforcing, certain errors are non-fatal.
2905 reason
= "Loading of unsigned module";
2908 reason
= "Loading of module with unsupported crypto";
2911 reason
= "Loading of module with unavailable key";
2913 if (is_module_sig_enforced()) {
2914 pr_notice("%s: %s is rejected\n", info
->name
, reason
);
2915 return -EKEYREJECTED
;
2918 return security_locked_down(LOCKDOWN_MODULE_SIGNATURE
);
2920 /* All other errors are fatal, including nomem, unparseable
2921 * signatures and signature check failures - even if signatures
2928 #else /* !CONFIG_MODULE_SIG */
2929 static int module_sig_check(struct load_info
*info
, int flags
)
2933 #endif /* !CONFIG_MODULE_SIG */
2935 /* Sanity checks against invalid binaries, wrong arch, weird elf version. */
2936 static int elf_header_check(struct load_info
*info
)
2938 if (info
->len
< sizeof(*(info
->hdr
)))
2941 if (memcmp(info
->hdr
->e_ident
, ELFMAG
, SELFMAG
) != 0
2942 || info
->hdr
->e_type
!= ET_REL
2943 || !elf_check_arch(info
->hdr
)
2944 || info
->hdr
->e_shentsize
!= sizeof(Elf_Shdr
))
2947 if (info
->hdr
->e_shoff
>= info
->len
2948 || (info
->hdr
->e_shnum
* sizeof(Elf_Shdr
) >
2949 info
->len
- info
->hdr
->e_shoff
))
2955 #define COPY_CHUNK_SIZE (16*PAGE_SIZE)
2957 static int copy_chunked_from_user(void *dst
, const void __user
*usrc
, unsigned long len
)
2960 unsigned long n
= min(len
, COPY_CHUNK_SIZE
);
2962 if (copy_from_user(dst
, usrc
, n
) != 0)
2972 #ifdef CONFIG_LIVEPATCH
2973 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
2975 if (get_modinfo(info
, "livepatch")) {
2977 add_taint_module(mod
, TAINT_LIVEPATCH
, LOCKDEP_STILL_OK
);
2978 pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n",
2984 #else /* !CONFIG_LIVEPATCH */
2985 static int check_modinfo_livepatch(struct module
*mod
, struct load_info
*info
)
2987 if (get_modinfo(info
, "livepatch")) {
2988 pr_err("%s: module is marked as livepatch module, but livepatch support is disabled",
2995 #endif /* CONFIG_LIVEPATCH */
2997 static void check_modinfo_retpoline(struct module
*mod
, struct load_info
*info
)
2999 if (retpoline_module_ok(get_modinfo(info
, "retpoline")))
3002 pr_warn("%s: loading module not compiled with retpoline compiler.\n",
3006 /* Sets info->hdr and info->len. */
3007 static int copy_module_from_user(const void __user
*umod
, unsigned long len
,
3008 struct load_info
*info
)
3013 if (info
->len
< sizeof(*(info
->hdr
)))
3016 err
= security_kernel_load_data(LOADING_MODULE
);
3020 /* Suck in entire file: we'll want most of it. */
3021 info
->hdr
= __vmalloc(info
->len
, GFP_KERNEL
| __GFP_NOWARN
);
3025 if (copy_chunked_from_user(info
->hdr
, umod
, info
->len
) != 0) {
3033 static void free_copy(struct load_info
*info
)
3038 static int rewrite_section_headers(struct load_info
*info
, int flags
)
3042 /* This should always be true, but let's be sure. */
3043 info
->sechdrs
[0].sh_addr
= 0;
3045 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3046 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3047 if (shdr
->sh_type
!= SHT_NOBITS
3048 && info
->len
< shdr
->sh_offset
+ shdr
->sh_size
) {
3049 pr_err("Module len %lu truncated\n", info
->len
);
3053 /* Mark all sections sh_addr with their address in the
3055 shdr
->sh_addr
= (size_t)info
->hdr
+ shdr
->sh_offset
;
3057 #ifndef CONFIG_MODULE_UNLOAD
3058 /* Don't load .exit sections */
3059 if (module_exit_section(info
->secstrings
+shdr
->sh_name
))
3060 shdr
->sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3064 /* Track but don't keep modinfo and version sections. */
3065 info
->sechdrs
[info
->index
.vers
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3066 info
->sechdrs
[info
->index
.info
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3072 * Set up our basic convenience variables (pointers to section headers,
3073 * search for module section index etc), and do some basic section
3076 * Set info->mod to the temporary copy of the module in info->hdr. The final one
3077 * will be allocated in move_module().
3079 static int setup_load_info(struct load_info
*info
, int flags
)
3083 /* Set up the convenience variables */
3084 info
->sechdrs
= (void *)info
->hdr
+ info
->hdr
->e_shoff
;
3085 info
->secstrings
= (void *)info
->hdr
3086 + info
->sechdrs
[info
->hdr
->e_shstrndx
].sh_offset
;
3088 /* Try to find a name early so we can log errors with a module name */
3089 info
->index
.info
= find_sec(info
, ".modinfo");
3090 if (info
->index
.info
)
3091 info
->name
= get_modinfo(info
, "name");
3093 /* Find internal symbols and strings. */
3094 for (i
= 1; i
< info
->hdr
->e_shnum
; i
++) {
3095 if (info
->sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
3096 info
->index
.sym
= i
;
3097 info
->index
.str
= info
->sechdrs
[i
].sh_link
;
3098 info
->strtab
= (char *)info
->hdr
3099 + info
->sechdrs
[info
->index
.str
].sh_offset
;
3104 if (info
->index
.sym
== 0) {
3105 pr_warn("%s: module has no symbols (stripped?)\n",
3106 info
->name
?: "(missing .modinfo section or name field)");
3110 info
->index
.mod
= find_sec(info
, ".gnu.linkonce.this_module");
3111 if (!info
->index
.mod
) {
3112 pr_warn("%s: No module found in object\n",
3113 info
->name
?: "(missing .modinfo section or name field)");
3116 /* This is temporary: point mod into copy of data. */
3117 info
->mod
= (void *)info
->hdr
+ info
->sechdrs
[info
->index
.mod
].sh_offset
;
3120 * If we didn't load the .modinfo 'name' field earlier, fall back to
3121 * on-disk struct mod 'name' field.
3124 info
->name
= info
->mod
->name
;
3126 if (flags
& MODULE_INIT_IGNORE_MODVERSIONS
)
3127 info
->index
.vers
= 0; /* Pretend no __versions section! */
3129 info
->index
.vers
= find_sec(info
, "__versions");
3131 info
->index
.pcpu
= find_pcpusec(info
);
3136 static int check_modinfo(struct module
*mod
, struct load_info
*info
, int flags
)
3138 const char *modmagic
= get_modinfo(info
, "vermagic");
3141 if (flags
& MODULE_INIT_IGNORE_VERMAGIC
)
3144 /* This is allowed: modprobe --force will invalidate it. */
3146 err
= try_to_force_load(mod
, "bad vermagic");
3149 } else if (!same_magic(modmagic
, vermagic
, info
->index
.vers
)) {
3150 pr_err("%s: version magic '%s' should be '%s'\n",
3151 info
->name
, modmagic
, vermagic
);
3155 if (!get_modinfo(info
, "intree")) {
3156 if (!test_taint(TAINT_OOT_MODULE
))
3157 pr_warn("%s: loading out-of-tree module taints kernel.\n",
3159 add_taint_module(mod
, TAINT_OOT_MODULE
, LOCKDEP_STILL_OK
);
3162 check_modinfo_retpoline(mod
, info
);
3164 if (get_modinfo(info
, "staging")) {
3165 add_taint_module(mod
, TAINT_CRAP
, LOCKDEP_STILL_OK
);
3166 pr_warn("%s: module is from the staging directory, the quality "
3167 "is unknown, you have been warned.\n", mod
->name
);
3170 err
= check_modinfo_livepatch(mod
, info
);
3174 /* Set up license info based on the info section */
3175 set_license(mod
, get_modinfo(info
, "license"));
3180 static int find_module_sections(struct module
*mod
, struct load_info
*info
)
3182 mod
->kp
= section_objs(info
, "__param",
3183 sizeof(*mod
->kp
), &mod
->num_kp
);
3184 mod
->syms
= section_objs(info
, "__ksymtab",
3185 sizeof(*mod
->syms
), &mod
->num_syms
);
3186 mod
->crcs
= section_addr(info
, "__kcrctab");
3187 mod
->gpl_syms
= section_objs(info
, "__ksymtab_gpl",
3188 sizeof(*mod
->gpl_syms
),
3189 &mod
->num_gpl_syms
);
3190 mod
->gpl_crcs
= section_addr(info
, "__kcrctab_gpl");
3191 mod
->gpl_future_syms
= section_objs(info
,
3192 "__ksymtab_gpl_future",
3193 sizeof(*mod
->gpl_future_syms
),
3194 &mod
->num_gpl_future_syms
);
3195 mod
->gpl_future_crcs
= section_addr(info
, "__kcrctab_gpl_future");
3197 #ifdef CONFIG_UNUSED_SYMBOLS
3198 mod
->unused_syms
= section_objs(info
, "__ksymtab_unused",
3199 sizeof(*mod
->unused_syms
),
3200 &mod
->num_unused_syms
);
3201 mod
->unused_crcs
= section_addr(info
, "__kcrctab_unused");
3202 mod
->unused_gpl_syms
= section_objs(info
, "__ksymtab_unused_gpl",
3203 sizeof(*mod
->unused_gpl_syms
),
3204 &mod
->num_unused_gpl_syms
);
3205 mod
->unused_gpl_crcs
= section_addr(info
, "__kcrctab_unused_gpl");
3207 #ifdef CONFIG_CONSTRUCTORS
3208 mod
->ctors
= section_objs(info
, ".ctors",
3209 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3211 mod
->ctors
= section_objs(info
, ".init_array",
3212 sizeof(*mod
->ctors
), &mod
->num_ctors
);
3213 else if (find_sec(info
, ".init_array")) {
3215 * This shouldn't happen with same compiler and binutils
3216 * building all parts of the module.
3218 pr_warn("%s: has both .ctors and .init_array.\n",
3224 mod
->noinstr_text_start
= section_objs(info
, ".noinstr.text", 1,
3225 &mod
->noinstr_text_size
);
3227 #ifdef CONFIG_TRACEPOINTS
3228 mod
->tracepoints_ptrs
= section_objs(info
, "__tracepoints_ptrs",
3229 sizeof(*mod
->tracepoints_ptrs
),
3230 &mod
->num_tracepoints
);
3232 #ifdef CONFIG_TREE_SRCU
3233 mod
->srcu_struct_ptrs
= section_objs(info
, "___srcu_struct_ptrs",
3234 sizeof(*mod
->srcu_struct_ptrs
),
3235 &mod
->num_srcu_structs
);
3237 #ifdef CONFIG_BPF_EVENTS
3238 mod
->bpf_raw_events
= section_objs(info
, "__bpf_raw_tp_map",
3239 sizeof(*mod
->bpf_raw_events
),
3240 &mod
->num_bpf_raw_events
);
3242 #ifdef CONFIG_JUMP_LABEL
3243 mod
->jump_entries
= section_objs(info
, "__jump_table",
3244 sizeof(*mod
->jump_entries
),
3245 &mod
->num_jump_entries
);
3247 #ifdef CONFIG_EVENT_TRACING
3248 mod
->trace_events
= section_objs(info
, "_ftrace_events",
3249 sizeof(*mod
->trace_events
),
3250 &mod
->num_trace_events
);
3251 mod
->trace_evals
= section_objs(info
, "_ftrace_eval_map",
3252 sizeof(*mod
->trace_evals
),
3253 &mod
->num_trace_evals
);
3255 #ifdef CONFIG_TRACING
3256 mod
->trace_bprintk_fmt_start
= section_objs(info
, "__trace_printk_fmt",
3257 sizeof(*mod
->trace_bprintk_fmt_start
),
3258 &mod
->num_trace_bprintk_fmt
);
3260 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
3261 /* sechdrs[0].sh_size is always zero */
3262 mod
->ftrace_callsites
= section_objs(info
, FTRACE_CALLSITE_SECTION
,
3263 sizeof(*mod
->ftrace_callsites
),
3264 &mod
->num_ftrace_callsites
);
3266 #ifdef CONFIG_FUNCTION_ERROR_INJECTION
3267 mod
->ei_funcs
= section_objs(info
, "_error_injection_whitelist",
3268 sizeof(*mod
->ei_funcs
),
3269 &mod
->num_ei_funcs
);
3271 #ifdef CONFIG_KPROBES
3272 mod
->kprobes_text_start
= section_objs(info
, ".kprobes.text", 1,
3273 &mod
->kprobes_text_size
);
3274 mod
->kprobe_blacklist
= section_objs(info
, "_kprobe_blacklist",
3275 sizeof(unsigned long),
3276 &mod
->num_kprobe_blacklist
);
3278 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
3279 mod
->static_call_sites
= section_objs(info
, ".static_call_sites",
3280 sizeof(*mod
->static_call_sites
),
3281 &mod
->num_static_call_sites
);
3283 mod
->extable
= section_objs(info
, "__ex_table",
3284 sizeof(*mod
->extable
), &mod
->num_exentries
);
3286 if (section_addr(info
, "__obsparm"))
3287 pr_warn("%s: Ignoring obsolete parameters\n", mod
->name
);
3289 info
->debug
= section_objs(info
, "__dyndbg",
3290 sizeof(*info
->debug
), &info
->num_debug
);
3295 static int move_module(struct module
*mod
, struct load_info
*info
)
3300 /* Do the allocs. */
3301 ptr
= module_alloc(mod
->core_layout
.size
);
3303 * The pointer to this block is stored in the module structure
3304 * which is inside the block. Just mark it as not being a
3307 kmemleak_not_leak(ptr
);
3311 memset(ptr
, 0, mod
->core_layout
.size
);
3312 mod
->core_layout
.base
= ptr
;
3314 if (mod
->init_layout
.size
) {
3315 ptr
= module_alloc(mod
->init_layout
.size
);
3317 * The pointer to this block is stored in the module structure
3318 * which is inside the block. This block doesn't need to be
3319 * scanned as it contains data and code that will be freed
3320 * after the module is initialized.
3322 kmemleak_ignore(ptr
);
3324 module_memfree(mod
->core_layout
.base
);
3327 memset(ptr
, 0, mod
->init_layout
.size
);
3328 mod
->init_layout
.base
= ptr
;
3330 mod
->init_layout
.base
= NULL
;
3332 /* Transfer each section which specifies SHF_ALLOC */
3333 pr_debug("final section addresses:\n");
3334 for (i
= 0; i
< info
->hdr
->e_shnum
; i
++) {
3336 Elf_Shdr
*shdr
= &info
->sechdrs
[i
];
3338 if (!(shdr
->sh_flags
& SHF_ALLOC
))
3341 if (shdr
->sh_entsize
& INIT_OFFSET_MASK
)
3342 dest
= mod
->init_layout
.base
3343 + (shdr
->sh_entsize
& ~INIT_OFFSET_MASK
);
3345 dest
= mod
->core_layout
.base
+ shdr
->sh_entsize
;
3347 if (shdr
->sh_type
!= SHT_NOBITS
)
3348 memcpy(dest
, (void *)shdr
->sh_addr
, shdr
->sh_size
);
3349 /* Update sh_addr to point to copy in image. */
3350 shdr
->sh_addr
= (unsigned long)dest
;
3351 pr_debug("\t0x%lx %s\n",
3352 (long)shdr
->sh_addr
, info
->secstrings
+ shdr
->sh_name
);
3358 static int check_module_license_and_versions(struct module
*mod
)
3360 int prev_taint
= test_taint(TAINT_PROPRIETARY_MODULE
);
3363 * ndiswrapper is under GPL by itself, but loads proprietary modules.
3364 * Don't use add_taint_module(), as it would prevent ndiswrapper from
3365 * using GPL-only symbols it needs.
3367 if (strcmp(mod
->name
, "ndiswrapper") == 0)
3368 add_taint(TAINT_PROPRIETARY_MODULE
, LOCKDEP_NOW_UNRELIABLE
);
3370 /* driverloader was caught wrongly pretending to be under GPL */
3371 if (strcmp(mod
->name
, "driverloader") == 0)
3372 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3373 LOCKDEP_NOW_UNRELIABLE
);
3375 /* lve claims to be GPL but upstream won't provide source */
3376 if (strcmp(mod
->name
, "lve") == 0)
3377 add_taint_module(mod
, TAINT_PROPRIETARY_MODULE
,
3378 LOCKDEP_NOW_UNRELIABLE
);
3380 if (!prev_taint
&& test_taint(TAINT_PROPRIETARY_MODULE
))
3381 pr_warn("%s: module license taints kernel.\n", mod
->name
);
3383 #ifdef CONFIG_MODVERSIONS
3384 if ((mod
->num_syms
&& !mod
->crcs
)
3385 || (mod
->num_gpl_syms
&& !mod
->gpl_crcs
)
3386 || (mod
->num_gpl_future_syms
&& !mod
->gpl_future_crcs
)
3387 #ifdef CONFIG_UNUSED_SYMBOLS
3388 || (mod
->num_unused_syms
&& !mod
->unused_crcs
)
3389 || (mod
->num_unused_gpl_syms
&& !mod
->unused_gpl_crcs
)
3392 return try_to_force_load(mod
,
3393 "no versions for exported symbols");
3399 static void flush_module_icache(const struct module
*mod
)
3402 * Flush the instruction cache, since we've played with text.
3403 * Do it before processing of module parameters, so the module
3404 * can provide parameter accessor functions of its own.
3406 if (mod
->init_layout
.base
)
3407 flush_icache_range((unsigned long)mod
->init_layout
.base
,
3408 (unsigned long)mod
->init_layout
.base
3409 + mod
->init_layout
.size
);
3410 flush_icache_range((unsigned long)mod
->core_layout
.base
,
3411 (unsigned long)mod
->core_layout
.base
+ mod
->core_layout
.size
);
3414 int __weak
module_frob_arch_sections(Elf_Ehdr
*hdr
,
3422 /* module_blacklist is a comma-separated list of module names */
3423 static char *module_blacklist
;
3424 static bool blacklisted(const char *module_name
)
3429 if (!module_blacklist
)
3432 for (p
= module_blacklist
; *p
; p
+= len
) {
3433 len
= strcspn(p
, ",");
3434 if (strlen(module_name
) == len
&& !memcmp(module_name
, p
, len
))
3441 core_param(module_blacklist
, module_blacklist
, charp
, 0400);
3443 static struct module
*layout_and_allocate(struct load_info
*info
, int flags
)
3449 err
= check_modinfo(info
->mod
, info
, flags
);
3451 return ERR_PTR(err
);
3453 /* Allow arches to frob section contents and sizes. */
3454 err
= module_frob_arch_sections(info
->hdr
, info
->sechdrs
,
3455 info
->secstrings
, info
->mod
);
3457 return ERR_PTR(err
);
3459 err
= module_enforce_rwx_sections(info
->hdr
, info
->sechdrs
,
3460 info
->secstrings
, info
->mod
);
3462 return ERR_PTR(err
);
3464 /* We will do a special allocation for per-cpu sections later. */
3465 info
->sechdrs
[info
->index
.pcpu
].sh_flags
&= ~(unsigned long)SHF_ALLOC
;
3468 * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
3469 * layout_sections() can put it in the right place.
3470 * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
3472 ndx
= find_sec(info
, ".data..ro_after_init");
3474 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3476 * Mark the __jump_table section as ro_after_init as well: these data
3477 * structures are never modified, with the exception of entries that
3478 * refer to code in the __init section, which are annotated as such
3479 * at module load time.
3481 ndx
= find_sec(info
, "__jump_table");
3483 info
->sechdrs
[ndx
].sh_flags
|= SHF_RO_AFTER_INIT
;
3485 /* Determine total sizes, and put offsets in sh_entsize. For now
3486 this is done generically; there doesn't appear to be any
3487 special cases for the architectures. */
3488 layout_sections(info
->mod
, info
);
3489 layout_symtab(info
->mod
, info
);
3491 /* Allocate and move to the final place */
3492 err
= move_module(info
->mod
, info
);
3494 return ERR_PTR(err
);
3496 /* Module has been copied to its final place now: return it. */
3497 mod
= (void *)info
->sechdrs
[info
->index
.mod
].sh_addr
;
3498 kmemleak_load_module(mod
, info
);
3502 /* mod is no longer valid after this! */
3503 static void module_deallocate(struct module
*mod
, struct load_info
*info
)
3505 percpu_modfree(mod
);
3506 module_arch_freeing_init(mod
);
3507 module_memfree(mod
->init_layout
.base
);
3508 module_memfree(mod
->core_layout
.base
);
3511 int __weak
module_finalize(const Elf_Ehdr
*hdr
,
3512 const Elf_Shdr
*sechdrs
,
3518 static int post_relocation(struct module
*mod
, const struct load_info
*info
)
3520 /* Sort exception table now relocations are done. */
3521 sort_extable(mod
->extable
, mod
->extable
+ mod
->num_exentries
);
3523 /* Copy relocated percpu area over. */
3524 percpu_modcopy(mod
, (void *)info
->sechdrs
[info
->index
.pcpu
].sh_addr
,
3525 info
->sechdrs
[info
->index
.pcpu
].sh_size
);
3527 /* Setup kallsyms-specific fields. */
3528 add_kallsyms(mod
, info
);
3530 /* Arch-specific module finalizing. */
3531 return module_finalize(info
->hdr
, info
->sechdrs
, mod
);
3534 /* Is this module of this name done loading? No locks held. */
3535 static bool finished_loading(const char *name
)
3541 * The module_mutex should not be a heavily contended lock;
3542 * if we get the occasional sleep here, we'll go an extra iteration
3543 * in the wait_event_interruptible(), which is harmless.
3545 sched_annotate_sleep();
3546 mutex_lock(&module_mutex
);
3547 mod
= find_module_all(name
, strlen(name
), true);
3548 ret
= !mod
|| mod
->state
== MODULE_STATE_LIVE
;
3549 mutex_unlock(&module_mutex
);
3554 /* Call module constructors. */
3555 static void do_mod_ctors(struct module
*mod
)
3557 #ifdef CONFIG_CONSTRUCTORS
3560 for (i
= 0; i
< mod
->num_ctors
; i
++)
3565 /* For freeing module_init on success, in case kallsyms traversing */
3566 struct mod_initfree
{
3567 struct llist_node node
;
3571 static void do_free_init(struct work_struct
*w
)
3573 struct llist_node
*pos
, *n
, *list
;
3574 struct mod_initfree
*initfree
;
3576 list
= llist_del_all(&init_free_list
);
3580 llist_for_each_safe(pos
, n
, list
) {
3581 initfree
= container_of(pos
, struct mod_initfree
, node
);
3582 module_memfree(initfree
->module_init
);
3587 static int __init
modules_wq_init(void)
3589 INIT_WORK(&init_free_wq
, do_free_init
);
3590 init_llist_head(&init_free_list
);
3593 module_init(modules_wq_init
);
3596 * This is where the real work happens.
3598 * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb
3599 * helper command 'lx-symbols'.
3601 static noinline
int do_init_module(struct module
*mod
)
3604 struct mod_initfree
*freeinit
;
3606 freeinit
= kmalloc(sizeof(*freeinit
), GFP_KERNEL
);
3611 freeinit
->module_init
= mod
->init_layout
.base
;
3614 * We want to find out whether @mod uses async during init. Clear
3615 * PF_USED_ASYNC. async_schedule*() will set it.
3617 current
->flags
&= ~PF_USED_ASYNC
;
3620 /* Start the module */
3621 if (mod
->init
!= NULL
)
3622 ret
= do_one_initcall(mod
->init
);
3624 goto fail_free_freeinit
;
3627 pr_warn("%s: '%s'->init suspiciously returned %d, it should "
3628 "follow 0/-E convention\n"
3629 "%s: loading module anyway...\n",
3630 __func__
, mod
->name
, ret
, __func__
);
3634 /* Now it's a first class citizen! */
3635 mod
->state
= MODULE_STATE_LIVE
;
3636 blocking_notifier_call_chain(&module_notify_list
,
3637 MODULE_STATE_LIVE
, mod
);
3640 * We need to finish all async code before the module init sequence
3641 * is done. This has potential to deadlock. For example, a newly
3642 * detected block device can trigger request_module() of the
3643 * default iosched from async probing task. Once userland helper
3644 * reaches here, async_synchronize_full() will wait on the async
3645 * task waiting on request_module() and deadlock.
3647 * This deadlock is avoided by perfomring async_synchronize_full()
3648 * iff module init queued any async jobs. This isn't a full
3649 * solution as it will deadlock the same if module loading from
3650 * async jobs nests more than once; however, due to the various
3651 * constraints, this hack seems to be the best option for now.
3652 * Please refer to the following thread for details.
3654 * http://thread.gmane.org/gmane.linux.kernel/1420814
3656 if (!mod
->async_probe_requested
&& (current
->flags
& PF_USED_ASYNC
))
3657 async_synchronize_full();
3659 ftrace_free_mem(mod
, mod
->init_layout
.base
, mod
->init_layout
.base
+
3660 mod
->init_layout
.size
);
3661 mutex_lock(&module_mutex
);
3662 /* Drop initial reference. */
3664 trim_init_extable(mod
);
3665 #ifdef CONFIG_KALLSYMS
3666 /* Switch to core kallsyms now init is done: kallsyms may be walking! */
3667 rcu_assign_pointer(mod
->kallsyms
, &mod
->core_kallsyms
);
3669 module_enable_ro(mod
, true);
3670 mod_tree_remove_init(mod
);
3671 module_arch_freeing_init(mod
);
3672 mod
->init_layout
.base
= NULL
;
3673 mod
->init_layout
.size
= 0;
3674 mod
->init_layout
.ro_size
= 0;
3675 mod
->init_layout
.ro_after_init_size
= 0;
3676 mod
->init_layout
.text_size
= 0;
3678 * We want to free module_init, but be aware that kallsyms may be
3679 * walking this with preempt disabled. In all the failure paths, we
3680 * call synchronize_rcu(), but we don't want to slow down the success
3681 * path. module_memfree() cannot be called in an interrupt, so do the
3682 * work and call synchronize_rcu() in a work queue.
3684 * Note that module_alloc() on most architectures creates W+X page
3685 * mappings which won't be cleaned up until do_free_init() runs. Any
3686 * code such as mark_rodata_ro() which depends on those mappings to
3687 * be cleaned up needs to sync with the queued work - ie
3690 if (llist_add(&freeinit
->node
, &init_free_list
))
3691 schedule_work(&init_free_wq
);
3693 mutex_unlock(&module_mutex
);
3694 wake_up_all(&module_wq
);
3701 /* Try to protect us from buggy refcounters. */
3702 mod
->state
= MODULE_STATE_GOING
;
3705 blocking_notifier_call_chain(&module_notify_list
,
3706 MODULE_STATE_GOING
, mod
);
3707 klp_module_going(mod
);
3708 ftrace_release_mod(mod
);
3710 wake_up_all(&module_wq
);
3714 static int may_init_module(void)
3716 if (!capable(CAP_SYS_MODULE
) || modules_disabled
)
3723 * We try to place it in the list now to make sure it's unique before
3724 * we dedicate too many resources. In particular, temporary percpu
3725 * memory exhaustion.
3727 static int add_unformed_module(struct module
*mod
)
3732 mod
->state
= MODULE_STATE_UNFORMED
;
3735 mutex_lock(&module_mutex
);
3736 old
= find_module_all(mod
->name
, strlen(mod
->name
), true);
3738 if (old
->state
!= MODULE_STATE_LIVE
) {
3739 /* Wait in case it fails to load. */
3740 mutex_unlock(&module_mutex
);
3741 err
= wait_event_interruptible(module_wq
,
3742 finished_loading(mod
->name
));
3750 mod_update_bounds(mod
);
3751 list_add_rcu(&mod
->list
, &modules
);
3752 mod_tree_insert(mod
);
3756 mutex_unlock(&module_mutex
);
3761 static int complete_formation(struct module
*mod
, struct load_info
*info
)
3765 mutex_lock(&module_mutex
);
3767 /* Find duplicate symbols (must be called under lock). */
3768 err
= verify_exported_symbols(mod
);
3772 /* This relies on module_mutex for list integrity. */
3773 module_bug_finalize(info
->hdr
, info
->sechdrs
, mod
);
3775 module_enable_ro(mod
, false);
3776 module_enable_nx(mod
);
3777 module_enable_x(mod
);
3779 /* Mark state as coming so strong_try_module_get() ignores us,
3780 * but kallsyms etc. can see us. */
3781 mod
->state
= MODULE_STATE_COMING
;
3782 mutex_unlock(&module_mutex
);
3787 mutex_unlock(&module_mutex
);
3791 static int prepare_coming_module(struct module
*mod
)
3795 ftrace_module_enable(mod
);
3796 err
= klp_module_coming(mod
);
3800 err
= blocking_notifier_call_chain_robust(&module_notify_list
,
3801 MODULE_STATE_COMING
, MODULE_STATE_GOING
, mod
);
3802 err
= notifier_to_errno(err
);
3804 klp_module_going(mod
);
3809 static int unknown_module_param_cb(char *param
, char *val
, const char *modname
,
3812 struct module
*mod
= arg
;
3815 if (strcmp(param
, "async_probe") == 0) {
3816 mod
->async_probe_requested
= true;
3820 /* Check for magic 'dyndbg' arg */
3821 ret
= ddebug_dyndbg_module_param_cb(param
, val
, modname
);
3823 pr_warn("%s: unknown parameter '%s' ignored\n", modname
, param
);
3827 /* Allocate and load the module: note that size of section 0 is always
3828 zero, and we rely on this for optional sections. */
3829 static int load_module(struct load_info
*info
, const char __user
*uargs
,
3836 err
= elf_header_check(info
);
3840 err
= setup_load_info(info
, flags
);
3844 if (blacklisted(info
->name
)) {
3849 err
= module_sig_check(info
, flags
);
3853 err
= rewrite_section_headers(info
, flags
);
3857 /* Check module struct version now, before we try to use module. */
3858 if (!check_modstruct_version(info
, info
->mod
)) {
3863 /* Figure out module layout, and allocate all the memory. */
3864 mod
= layout_and_allocate(info
, flags
);
3870 audit_log_kern_module(mod
->name
);
3872 /* Reserve our place in the list. */
3873 err
= add_unformed_module(mod
);
3877 #ifdef CONFIG_MODULE_SIG
3878 mod
->sig_ok
= info
->sig_ok
;
3880 pr_notice_once("%s: module verification failed: signature "
3881 "and/or required key missing - tainting "
3882 "kernel\n", mod
->name
);
3883 add_taint_module(mod
, TAINT_UNSIGNED_MODULE
, LOCKDEP_STILL_OK
);
3887 /* To avoid stressing percpu allocator, do this once we're unique. */
3888 err
= percpu_modalloc(mod
, info
);
3892 /* Now module is in final location, initialize linked lists, etc. */
3893 err
= module_unload_init(mod
);
3897 init_param_lock(mod
);
3899 /* Now we've got everything in the final locations, we can
3900 * find optional sections. */
3901 err
= find_module_sections(mod
, info
);
3905 err
= check_module_license_and_versions(mod
);
3909 /* Set up MODINFO_ATTR fields */
3910 setup_modinfo(mod
, info
);
3912 /* Fix up syms, so that st_value is a pointer to location. */
3913 err
= simplify_symbols(mod
, info
);
3917 err
= apply_relocations(mod
, info
);
3921 err
= post_relocation(mod
, info
);
3925 flush_module_icache(mod
);
3927 /* Now copy in args */
3928 mod
->args
= strndup_user(uargs
, ~0UL >> 1);
3929 if (IS_ERR(mod
->args
)) {
3930 err
= PTR_ERR(mod
->args
);
3931 goto free_arch_cleanup
;
3934 dynamic_debug_setup(mod
, info
->debug
, info
->num_debug
);
3936 /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
3937 ftrace_module_init(mod
);
3939 /* Finally it's fully formed, ready to start executing. */
3940 err
= complete_formation(mod
, info
);
3942 goto ddebug_cleanup
;
3944 err
= prepare_coming_module(mod
);
3948 /* Module is ready to execute: parsing args may do that. */
3949 after_dashes
= parse_args(mod
->name
, mod
->args
, mod
->kp
, mod
->num_kp
,
3951 unknown_module_param_cb
);
3952 if (IS_ERR(after_dashes
)) {
3953 err
= PTR_ERR(after_dashes
);
3954 goto coming_cleanup
;
3955 } else if (after_dashes
) {
3956 pr_warn("%s: parameters '%s' after `--' ignored\n",
3957 mod
->name
, after_dashes
);
3960 /* Link in to sysfs. */
3961 err
= mod_sysfs_setup(mod
, info
, mod
->kp
, mod
->num_kp
);
3963 goto coming_cleanup
;
3965 if (is_livepatch_module(mod
)) {
3966 err
= copy_module_elf(mod
, info
);
3971 /* Get rid of temporary copy. */
3975 trace_module_load(mod
);
3977 return do_init_module(mod
);
3980 mod_sysfs_teardown(mod
);
3982 mod
->state
= MODULE_STATE_GOING
;
3983 destroy_params(mod
->kp
, mod
->num_kp
);
3984 blocking_notifier_call_chain(&module_notify_list
,
3985 MODULE_STATE_GOING
, mod
);
3986 klp_module_going(mod
);
3988 /* module_bug_cleanup needs module_mutex protection */
3989 mutex_lock(&module_mutex
);
3990 module_bug_cleanup(mod
);
3991 mutex_unlock(&module_mutex
);
3994 ftrace_release_mod(mod
);
3995 dynamic_debug_remove(mod
, info
->debug
);
3999 module_arch_cleanup(mod
);
4003 module_unload_free(mod
);
4005 mutex_lock(&module_mutex
);
4006 /* Unlink carefully: kallsyms could be walking list. */
4007 list_del_rcu(&mod
->list
);
4008 mod_tree_remove(mod
);
4009 wake_up_all(&module_wq
);
4010 /* Wait for RCU-sched synchronizing before releasing mod->list. */
4012 mutex_unlock(&module_mutex
);
4014 /* Free lock-classes; relies on the preceding sync_rcu() */
4015 lockdep_free_key_range(mod
->core_layout
.base
, mod
->core_layout
.size
);
4017 module_deallocate(mod
, info
);
4023 SYSCALL_DEFINE3(init_module
, void __user
*, umod
,
4024 unsigned long, len
, const char __user
*, uargs
)
4027 struct load_info info
= { };
4029 err
= may_init_module();
4033 pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
4036 err
= copy_module_from_user(umod
, len
, &info
);
4040 return load_module(&info
, uargs
, 0);
4043 SYSCALL_DEFINE3(finit_module
, int, fd
, const char __user
*, uargs
, int, flags
)
4045 struct load_info info
= { };
4050 err
= may_init_module();
4054 pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd
, uargs
, flags
);
4056 if (flags
& ~(MODULE_INIT_IGNORE_MODVERSIONS
4057 |MODULE_INIT_IGNORE_VERMAGIC
))
4060 err
= kernel_read_file_from_fd(fd
, &hdr
, &size
, INT_MAX
,
4067 return load_module(&info
, uargs
, flags
);
4070 static inline int within(unsigned long addr
, void *start
, unsigned long size
)
4072 return ((void *)addr
>= start
&& (void *)addr
< start
+ size
);
4075 #ifdef CONFIG_KALLSYMS
4077 * This ignores the intensely annoying "mapping symbols" found
4078 * in ARM ELF files: $a, $t and $d.
4080 static inline int is_arm_mapping_symbol(const char *str
)
4082 if (str
[0] == '.' && str
[1] == 'L')
4084 return str
[0] == '$' && strchr("axtd", str
[1])
4085 && (str
[2] == '\0' || str
[2] == '.');
4088 static const char *kallsyms_symbol_name(struct mod_kallsyms
*kallsyms
, unsigned int symnum
)
4090 return kallsyms
->strtab
+ kallsyms
->symtab
[symnum
].st_name
;
4094 * Given a module and address, find the corresponding symbol and return its name
4095 * while providing its size and offset if needed.
4097 static const char *find_kallsyms_symbol(struct module
*mod
,
4099 unsigned long *size
,
4100 unsigned long *offset
)
4102 unsigned int i
, best
= 0;
4103 unsigned long nextval
, bestval
;
4104 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4106 /* At worse, next value is at end of module */
4107 if (within_module_init(addr
, mod
))
4108 nextval
= (unsigned long)mod
->init_layout
.base
+mod
->init_layout
.text_size
;
4110 nextval
= (unsigned long)mod
->core_layout
.base
+mod
->core_layout
.text_size
;
4112 bestval
= kallsyms_symbol_value(&kallsyms
->symtab
[best
]);
4114 /* Scan for closest preceding symbol, and next symbol. (ELF
4115 starts real symbols at 1). */
4116 for (i
= 1; i
< kallsyms
->num_symtab
; i
++) {
4117 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4118 unsigned long thisval
= kallsyms_symbol_value(sym
);
4120 if (sym
->st_shndx
== SHN_UNDEF
)
4123 /* We ignore unnamed symbols: they're uninformative
4124 * and inserted at a whim. */
4125 if (*kallsyms_symbol_name(kallsyms
, i
) == '\0'
4126 || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms
, i
)))
4129 if (thisval
<= addr
&& thisval
> bestval
) {
4133 if (thisval
> addr
&& thisval
< nextval
)
4141 *size
= nextval
- bestval
;
4143 *offset
= addr
- bestval
;
4145 return kallsyms_symbol_name(kallsyms
, best
);
4148 void * __weak
dereference_module_function_descriptor(struct module
*mod
,
4154 /* For kallsyms to ask for address resolution. NULL means not found. Careful
4155 * not to lock to avoid deadlock on oopses, simply disable preemption. */
4156 const char *module_address_lookup(unsigned long addr
,
4157 unsigned long *size
,
4158 unsigned long *offset
,
4162 const char *ret
= NULL
;
4166 mod
= __module_address(addr
);
4169 *modname
= mod
->name
;
4171 ret
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4173 /* Make a copy in here where it's safe */
4175 strncpy(namebuf
, ret
, KSYM_NAME_LEN
- 1);
4183 int lookup_module_symbol_name(unsigned long addr
, char *symname
)
4188 list_for_each_entry_rcu(mod
, &modules
, list
) {
4189 if (mod
->state
== MODULE_STATE_UNFORMED
)
4191 if (within_module(addr
, mod
)) {
4194 sym
= find_kallsyms_symbol(mod
, addr
, NULL
, NULL
);
4198 strlcpy(symname
, sym
, KSYM_NAME_LEN
);
4208 int lookup_module_symbol_attrs(unsigned long addr
, unsigned long *size
,
4209 unsigned long *offset
, char *modname
, char *name
)
4214 list_for_each_entry_rcu(mod
, &modules
, list
) {
4215 if (mod
->state
== MODULE_STATE_UNFORMED
)
4217 if (within_module(addr
, mod
)) {
4220 sym
= find_kallsyms_symbol(mod
, addr
, size
, offset
);
4224 strlcpy(modname
, mod
->name
, MODULE_NAME_LEN
);
4226 strlcpy(name
, sym
, KSYM_NAME_LEN
);
4236 int module_get_kallsym(unsigned int symnum
, unsigned long *value
, char *type
,
4237 char *name
, char *module_name
, int *exported
)
4242 list_for_each_entry_rcu(mod
, &modules
, list
) {
4243 struct mod_kallsyms
*kallsyms
;
4245 if (mod
->state
== MODULE_STATE_UNFORMED
)
4247 kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4248 if (symnum
< kallsyms
->num_symtab
) {
4249 const Elf_Sym
*sym
= &kallsyms
->symtab
[symnum
];
4251 *value
= kallsyms_symbol_value(sym
);
4252 *type
= kallsyms
->typetab
[symnum
];
4253 strlcpy(name
, kallsyms_symbol_name(kallsyms
, symnum
), KSYM_NAME_LEN
);
4254 strlcpy(module_name
, mod
->name
, MODULE_NAME_LEN
);
4255 *exported
= is_exported(name
, *value
, mod
);
4259 symnum
-= kallsyms
->num_symtab
;
4265 /* Given a module and name of symbol, find and return the symbol's value */
4266 static unsigned long find_kallsyms_symbol_value(struct module
*mod
, const char *name
)
4269 struct mod_kallsyms
*kallsyms
= rcu_dereference_sched(mod
->kallsyms
);
4271 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4272 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4274 if (strcmp(name
, kallsyms_symbol_name(kallsyms
, i
)) == 0 &&
4275 sym
->st_shndx
!= SHN_UNDEF
)
4276 return kallsyms_symbol_value(sym
);
4281 /* Look for this name: can be of form module:name. */
4282 unsigned long module_kallsyms_lookup_name(const char *name
)
4286 unsigned long ret
= 0;
4288 /* Don't lock: we're in enough trouble already. */
4290 if ((colon
= strnchr(name
, MODULE_NAME_LEN
, ':')) != NULL
) {
4291 if ((mod
= find_module_all(name
, colon
- name
, false)) != NULL
)
4292 ret
= find_kallsyms_symbol_value(mod
, colon
+1);
4294 list_for_each_entry_rcu(mod
, &modules
, list
) {
4295 if (mod
->state
== MODULE_STATE_UNFORMED
)
4297 if ((ret
= find_kallsyms_symbol_value(mod
, name
)) != 0)
4305 int module_kallsyms_on_each_symbol(int (*fn
)(void *, const char *,
4306 struct module
*, unsigned long),
4313 module_assert_mutex();
4315 list_for_each_entry(mod
, &modules
, list
) {
4316 /* We hold module_mutex: no need for rcu_dereference_sched */
4317 struct mod_kallsyms
*kallsyms
= mod
->kallsyms
;
4319 if (mod
->state
== MODULE_STATE_UNFORMED
)
4321 for (i
= 0; i
< kallsyms
->num_symtab
; i
++) {
4322 const Elf_Sym
*sym
= &kallsyms
->symtab
[i
];
4324 if (sym
->st_shndx
== SHN_UNDEF
)
4327 ret
= fn(data
, kallsyms_symbol_name(kallsyms
, i
),
4328 mod
, kallsyms_symbol_value(sym
));
4335 #endif /* CONFIG_KALLSYMS */
4337 /* Maximum number of characters written by module_flags() */
4338 #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
4340 /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */
4341 static char *module_flags(struct module
*mod
, char *buf
)
4345 BUG_ON(mod
->state
== MODULE_STATE_UNFORMED
);
4347 mod
->state
== MODULE_STATE_GOING
||
4348 mod
->state
== MODULE_STATE_COMING
) {
4350 bx
+= module_flags_taint(mod
, buf
+ bx
);
4351 /* Show a - for module-is-being-unloaded */
4352 if (mod
->state
== MODULE_STATE_GOING
)
4354 /* Show a + for module-is-being-loaded */
4355 if (mod
->state
== MODULE_STATE_COMING
)
4364 #ifdef CONFIG_PROC_FS
4365 /* Called by the /proc file system to return a list of modules. */
4366 static void *m_start(struct seq_file
*m
, loff_t
*pos
)
4368 mutex_lock(&module_mutex
);
4369 return seq_list_start(&modules
, *pos
);
4372 static void *m_next(struct seq_file
*m
, void *p
, loff_t
*pos
)
4374 return seq_list_next(p
, &modules
, pos
);
4377 static void m_stop(struct seq_file
*m
, void *p
)
4379 mutex_unlock(&module_mutex
);
4382 static int m_show(struct seq_file
*m
, void *p
)
4384 struct module
*mod
= list_entry(p
, struct module
, list
);
4385 char buf
[MODULE_FLAGS_BUF_SIZE
];
4388 /* We always ignore unformed modules. */
4389 if (mod
->state
== MODULE_STATE_UNFORMED
)
4392 seq_printf(m
, "%s %u",
4393 mod
->name
, mod
->init_layout
.size
+ mod
->core_layout
.size
);
4394 print_unload_info(m
, mod
);
4396 /* Informative for users. */
4397 seq_printf(m
, " %s",
4398 mod
->state
== MODULE_STATE_GOING
? "Unloading" :
4399 mod
->state
== MODULE_STATE_COMING
? "Loading" :
4401 /* Used by oprofile and other similar tools. */
4402 value
= m
->private ? NULL
: mod
->core_layout
.base
;
4403 seq_printf(m
, " 0x%px", value
);
4407 seq_printf(m
, " %s", module_flags(mod
, buf
));
4413 /* Format: modulename size refcount deps address
4415 Where refcount is a number or -, and deps is a comma-separated list
4418 static const struct seq_operations modules_op
= {
4426 * This also sets the "private" pointer to non-NULL if the
4427 * kernel pointers should be hidden (so you can just test
4428 * "m->private" to see if you should keep the values private).
4430 * We use the same logic as for /proc/kallsyms.
4432 static int modules_open(struct inode
*inode
, struct file
*file
)
4434 int err
= seq_open(file
, &modules_op
);
4437 struct seq_file
*m
= file
->private_data
;
4438 m
->private = kallsyms_show_value(file
->f_cred
) ? NULL
: (void *)8ul;
4444 static const struct proc_ops modules_proc_ops
= {
4445 .proc_flags
= PROC_ENTRY_PERMANENT
,
4446 .proc_open
= modules_open
,
4447 .proc_read
= seq_read
,
4448 .proc_lseek
= seq_lseek
,
4449 .proc_release
= seq_release
,
4452 static int __init
proc_modules_init(void)
4454 proc_create("modules", 0, NULL
, &modules_proc_ops
);
4457 module_init(proc_modules_init
);
4460 /* Given an address, look for it in the module exception tables. */
4461 const struct exception_table_entry
*search_module_extables(unsigned long addr
)
4463 const struct exception_table_entry
*e
= NULL
;
4467 mod
= __module_address(addr
);
4471 if (!mod
->num_exentries
)
4474 e
= search_extable(mod
->extable
,
4481 * Now, if we found one, we are running inside it now, hence
4482 * we cannot unload the module, hence no refcnt needed.
4488 * is_module_address - is this address inside a module?
4489 * @addr: the address to check.
4491 * See is_module_text_address() if you simply want to see if the address
4492 * is code (not data).
4494 bool is_module_address(unsigned long addr
)
4499 ret
= __module_address(addr
) != NULL
;
4506 * __module_address - get the module which contains an address.
4507 * @addr: the address.
4509 * Must be called with preempt disabled or module mutex held so that
4510 * module doesn't get freed during this.
4512 struct module
*__module_address(unsigned long addr
)
4516 if (addr
< module_addr_min
|| addr
> module_addr_max
)
4519 module_assert_mutex_or_preempt();
4521 mod
= mod_find(addr
);
4523 BUG_ON(!within_module(addr
, mod
));
4524 if (mod
->state
== MODULE_STATE_UNFORMED
)
4531 * is_module_text_address - is this address inside module code?
4532 * @addr: the address to check.
4534 * See is_module_address() if you simply want to see if the address is
4535 * anywhere in a module. See kernel_text_address() for testing if an
4536 * address corresponds to kernel or module code.
4538 bool is_module_text_address(unsigned long addr
)
4543 ret
= __module_text_address(addr
) != NULL
;
4550 * __module_text_address - get the module whose code contains an address.
4551 * @addr: the address.
4553 * Must be called with preempt disabled or module mutex held so that
4554 * module doesn't get freed during this.
4556 struct module
*__module_text_address(unsigned long addr
)
4558 struct module
*mod
= __module_address(addr
);
4560 /* Make sure it's within the text section. */
4561 if (!within(addr
, mod
->init_layout
.base
, mod
->init_layout
.text_size
)
4562 && !within(addr
, mod
->core_layout
.base
, mod
->core_layout
.text_size
))
4568 /* Don't grab lock, we're oopsing. */
4569 void print_modules(void)
4572 char buf
[MODULE_FLAGS_BUF_SIZE
];
4574 printk(KERN_DEFAULT
"Modules linked in:");
4575 /* Most callers should already have preempt disabled, but make sure */
4577 list_for_each_entry_rcu(mod
, &modules
, list
) {
4578 if (mod
->state
== MODULE_STATE_UNFORMED
)
4580 pr_cont(" %s%s", mod
->name
, module_flags(mod
, buf
));
4583 if (last_unloaded_module
[0])
4584 pr_cont(" [last unloaded: %s]", last_unloaded_module
);
4588 #ifdef CONFIG_MODVERSIONS
4589 /* Generate the signature for all relevant module structures here.
4590 * If these change, we don't want to try to parse the module. */
4591 void module_layout(struct module
*mod
,
4592 struct modversion_info
*ver
,
4593 struct kernel_param
*kp
,
4594 struct kernel_symbol
*ks
,
4595 struct tracepoint
* const *tp
)
4598 EXPORT_SYMBOL(module_layout
);